Does any western European country prohibit its citizens from travelling to particular areas abroad? In several countries, including European countries, there are public worries about citizens travelling to Syria. Although those press reports are not always precise, what is usually meant is people travelling to territory controlled by Islamic State with the purpose of taking up residence. Some are arrested upon return. What are they arrested for? Does any country in Western Europe prohibit its citizens from travelling to an area controlled by an organisation designated as terrorist? That would leave journalists travelling to IS- or PKK-controlled areas in violation of the law, so I suspect not. Joining an organisation designated as terrorist is often prohibited, as is joining a foreign military. But does taking up residence in an area controlled by such an organisation constitute either of those? Or do legislators suspect anyone returning from Syria to have actively supported the Islamic State (para-)military forces and/or be preparing terrorist attacks at home? (This question is hypothetical. I am not asking for myself. I am not even asking for a friend.)
Regarding the situation in Germany, it is not a crime by itself to travel to Syria (or in fact any other country), nor to take residence there. When people are arrested after such a trip, it is because they are suspected of having committed a crime during their stay. In this context, the crime could be, e.g., murder, abduction, or rape, but there are more specialized crimes, too, such as: Forming terrorist organisations (§&nbsp;129a StGB; translation) Preparation of a serious violent offence endangering the state (§&nbsp;89a StGB; translation) Preparation of a serious violent offence includes participating in a terrorist training camp where people are taught how to use weapons, construct explosive devices, etc. The definition of the crime was recently extended such that it is already punishable to make an attempt at leaving Germany with the intention of travelling to and participating in such a training camp. It is important to note that this intention would need to be demonstrated in court in order to get someone convicted; and someone travelling with different intentions, such as a journalist, would obviously not render oneself liable to prosecution. Outside of criminal law, there are other measures that the authorities may take to try and prevent people from travelling abroad if they are suspected future terrorists. As these are administrative measures and not criminal prosecution, the requirements for evidence are less strict. It has long been possible under German law to deny someone a passport (§&nbsp;7 PaßG; translation), or to revoke a passport that was already issued. The idea is that, without passport, the destination country or any transit countries are going to reject the traveller. This didn’t work too well in the case of Syria because a national ID card is sufficient for German citizens travelling to Turkey, which shares a land border with Syria. Therefore, also very recently, it was made possible to deny or revoke an ID card in much the same way as a passport (§&nbsp;6a PAuswG; no translation currently available). (Note that the translations I linked to are official but non-authoritative. In particular, be warned that the translation for §&nbsp;89a StGB at least does not yet reflect the latest amendments.)
Your VPN scenario is why you have to show the banner to everyone. If you somehow knew beyond any doubt that someone was not in the EU, then you would not have to show a banner, but because you can't verify that, you should always show the banner. Doing so also protects against accidentally violating a similar law in another country; the GDPR is the best-known privacy law, but it is far from the only one. It's good practice to ask for people's permission before collecting their information anyway.
While it is from a different jurisdiction, the following goes to the heart of the matter: Arrest, when used in its ordinary and natural sense, means the apprehension of a person or the deprivation of a person's liberty. The question whether the person is under arrest or not depends not on the legality of the arrest, but on whether the person has been deprived of personal liberty of movement. Directorate of Enforcement v Deepak Mahajan, (1994) 3 SCC 440 at ¶46 (SC of India) In your example, the police officer has been deprived of "personal liberty of movement"; if they can still speak there would be no legal impediment to them placing the person who arrested them also under arrest. It would then be incumbent on both parties to deliver each other into lawful custody. The citizen would need to seek out a law enforcement officer to do this; the police officer has already done so, being their own law enforcement officer. After this, comes the paperwork.
In general the act must be a crime in both countries for an extradition to proceed, but the extradition treaty between countries A and B likely has more specific provisions as well. C's involvement is generally limited to consular assistance, but there have been instances where countries have offered to incarcerate their citizens for convictions in other countries. The country of citizenship certainly does not have priority to extradite or try its citizens, and it is unlikely that the country seeking to prosecute would have much interest in another country taking over the case.
You have the right to withhold this information; they have the right to withhold a passport. You do not have a right to a passport; it is a privilege and that privilege may be withdrawn at the discretion of the State Department for all sorts of reasons. As a US citizen you have a right to travel within the US; you don't need any papers for this. However, if you wish to cross an international border then both the country you are departing and the country you are arriving in will decide the circumstances under which you can.
Yes More exactly, nations will not regard places outside of their physical limits as outside of their jurisdictions. Overview Traditionally, a nation has regarded any ship flying its flag as under its jurisdiction, and a place where it may enforce its laws. More recently, many nations will undertake to enforce laws in cases where their citizens are the victims, or in some cases the perpetrators of crimes even within other nations, and more freely on the high seas outside the physical limits or territorial waters of any country. Historically, all nations undertook to enforce laws against piracy wherever they might be committed. Several countries, including the UK and the US, now treat the UN Law of the Sea convention as part of their national law, which defines as piracy: &quot;illegal acts of violence or detention ... against persons or property on board such ship or aircraft&quot; This would include the situation described in the question. Therefore such actions could and quite likely would be prosecuted by any of several countries, depending on the registry of the vessel and the nationalities of those involved. Sources 18 U.S. Code § 7 provides that: The term “special maritime and territorial jurisdiction of the United States”, as used in this title, includes: (1) The high seas, any other waters within the admiralty and maritime jurisdiction of the United States and out of the jurisdiction of any particular State, and any vessel belonging in whole or in part to the United States or any citizen thereof, or to any corporation created by or under the laws of the United States, or of any State, Territory, District, or possession thereof, when such vessel is within the admiralty and maritime jurisdiction of the United States and out of the jurisdiction of any particular State. ... (7) Any place outside the jurisdiction of any nation with respect to an offense by or against a national of the United States. (8) To the extent permitted by international law, any foreign vessel during a voyage having a scheduled departure from or arrival in the United States with respect to an offense committed by or against a national of the United States. This US DOJ page says: Among the offenses within the special maritime and territorial jurisdiction of the United States are the crimes of murder, manslaughter, maiming, kidnapping, rape, assault, and robbery. Pursuant to 18 U.S.C. § 7(1) there is also jurisdiction over such offenses when they are committed on the high seas or any other waters within the admiralty and maritime jurisdiction of the United States that is out of the jurisdiction of any particular state. See JM 9-20.000 et seq. The page &quot;Maritime Offenses&quot; from the law offices of Trombley and Hanes says: The Federal government also exercises jurisdiction over certain maritime offenses. There is Federal jurisdiction for offenses committed on American vessels in the territorial waters, harbors and inland waterways of foreign nations. See United States v. Flores, 289 U.S. 137 (1933). ... A number of Title 18 sections specifically declare certain conduct to be a Federal crime if committed “within the special maritime and territorial jurisdiction of the United States.” See, e.g., murder, 18 U.S.C. § 1111. In some instances, the Assimilative Crimes Act, 18 U.S.C. § 13, is also applicable. See also, 15 U.S.C. § 1175; 15 U.S.C. § 1243; 16 U.S.C. § 3372. 18 U.S. Code § 1111 (b) provides that: (b) Within the special maritime and territorial jurisdiction of the United States, Whoever is guilty of murder in the first degree shall be punished by death or by imprisonment for life; Whoever is guilty of murder in the second degree, shall be imprisoned for any term of years or for life. The Britannica Article on &quot;Piracy&quot; says: Because piracy has been regarded as an offense against the law of nations, the public vessels of any state have been permitted to seize a pirate ship, to bring it into port, to try the crew (regardless of their nationality or domicile), and, if they are found guilty, to punish them and to confiscate the ship. The UN page on Piracy says: The 1982 United Nations Convention on the Law of the Sea (UNCLOS) provides the framework for the repression of piracy under international law, in particular in its articles 100 to 107 and 110. The Security Council has repeatedly reaffirmed “that international law, as reflected in the United Nations Convention on the Law of the Sea of 10 December 1982 (‘The Convention’), sets out the legal framework applicable to combating piracy and armed robbery at sea, as well as other ocean activities” (Security Council resolution 1897 (2009), adopted on 30 November 2009). Article 100 of UNCLOS provides that “[a]ll States shall cooperate to the fullest possible extent in the repression of piracy on the high seas or in any other place outside the jurisdiction of any State.” The General Assembly has also repeatedly encouraged States to cooperate to address piracy and armed robbery at sea in its resolutions on oceans and the law of the sea. For example, in its resolution 64/71 of 4 December 2009, the General Assembly recognized “the crucial role of international cooperation at the global, regional, subregional and bilateral levels in combating, in accordance with international law, threats to maritime security, including piracy”. The UK Piracy Act of 1837 defined as a crime: Whosoever, with intent to commit or at the time of or immediately before or immediately after committing the crime of piracy in respect of any ship or vessel, shall assault, with intent to murder, any person being on board of or belonging to such ship or vessel, or shall stab, cut, or wound any such person, or unlawfully do any act by which the life of such person may be endangered, shall be guilty of felony... The more modern UK law, the Merchant Shipping and Maritime Security Act of 1997 embodies the UN law of the Sea convention, including its article 101, which says: Piracy consists of any of the following acts: (a) any illegal acts of violence or detention, or any act of depredation, committed for private ends by the crew or the passengers of a private ship or a private aircraft, and directed— (a) (i) on the high seas, against another ship or aircraft, or against persons or property on board such ship or aircraft; (a) (ii) against a ship, aircraft, persons or property in a place outside the jurisdiction of any State;
Part answer to Q1: Is my conceptualization correct? No, insofar that your Points 1 to 4 are all &quot;completely illegal&quot; regardless of how the authorities deal with them, and the rest are not, on the face of it, crimes but presumably civil wrongs (which can be dealt with by, for example, fines or restraint / good behaviour / banning orders etc without one having a &quot;criminal conviction&quot;). Also: if the authorities, for whatever reason, decide against dealing with crime then it hasn't been &quot;decriminalised&quot; - that is the remit of the law makers, not the law enforcers. It's still a crime but with a lower political/ operational etc priority.
In the US it is not a crime to be in the country illegally. As a general rule, it is not a crime for a removable alien to remain in the United States. Arizona v US So it's illegal, you get a state induced consequence (deportation) but it doesn't make you a criminal e.g. you don't go to jail for it. I have no idea if that's what's going on over there but it's a plausible explanation.