Under what circumstances can a subpoena be issued? I'm trying to help someone out on a different Stack Exchange website about a stolen device. Not many of us know many too much about the law. We are trying to figure out who has/where is the stolen device. We know the device manufacturer account system (I'm just avoiding stating the company name) will log all logins and where they came from. One of the things they log is an IP address which can be used to trace it to an extent. Unfortunately this information isn't public, and we think the only way to get this information would be with a subpoena. How could we get a subpoena issued to retrieve this information? Would there need to be an attempt to press charges in court to get a subpoena? Or can the police department issue one?
Law enforcement officers can obtain information with a search warrant, which is a document issued by a judge or magistrate that authorizes them to search for specific information or evidence based on "probable cause" to believe that it will inform the investigation or prosecution of a crime. A court can also issue a subpoena at the request of a party to a proceeding before it. Since in most cases only the state can bring criminal charges before a court, an individual would have to bring a civil complaint before a court in order to even request a subpoena related to his complaint. Also, it is up to the court to enforce its subpoenas: It's not like a warrant where you can then pursue the items subpoenaed through force. If the subject of a subpoena doesn't respond you have to ask the court to compel the party, which means you have to bring your complaint before a court that has jurisdiction over the party you wish to subpoena. This can be difficult when it involves a third party – especially a third party that would rather ignore or object to the subpoena than hand over the information. I.e., if you can't convince law enforcement to investigate the crime, and you can't convince the company in possession of the data that it's in its interest to help you, then you would most likely be facing a steep legal bill to get an attorney to successfully obtain the information through civil process.
IANAL, and as @GeorgeBailey suggests, you should ask one. That said, some aspects of your question are directly addressable with what we know. Does US law states anything about this? Yes. Federally this falls under the Wiretap Act, 18 U.S.C. §2511. Workplace monitoring generally falls under either the "System Administrator Exception" or under Consent. In general, continuing past a banner constitutes consent. Does company policy enforcement with such a warning over ride the right to not be subject to surveillance? In general, yes. You don't need to use the companies network if you don't want to consent - and they don't need to hire you if you don't want to use their network. But it's their network, and their rules apply. There are some nuances, and courts have found that the wording of the notice has made a difference in some cases, but overall, if the systems are properly posted with banners, then the employer may capture communications. See the "Bannering and Consent" section of this article from cybertelecom.org, e.g.: Even if no clicking is required, a user who sees the banner before logging on to the network has received notice of the monitoring. By using the network in light of the notice, the user impliedly consents to monitoring pursuant to 18 U.S.C. § 2511(2)(c)-(d). Note that stored data is covered by different laws than communications. It's a nuance. Is it ethical to sniff all the data without giving any other warning than the logon banner? "Ethical" is a very different question than "Legal", and largely more subjective. Most employers require signed consent for monitoring as a condition of employment, and use banners thereafter. That is ethical by my definition, in that it meets or exceeds the requirements of the law, and does not mislead or use subterfuge. The tone of your question suggests you find it distasteful, and therefore probably it violates your personal code of ethics.
We need to assume that the stop was legal (not a high hurdle to clear), that is, there was some reason to stop you. Even so, following Utah v. Strieff, police don't actually have to have a reasonable suspicion to stop you and if in the course of an ID check they discover that you have a warrant out for your arrest, the arrest is still legal. So if the police stop you, RCW 46.61.020(1) says: It is unlawful for any person while operating or in charge of any vehicle to refuse when requested by a police officer to give his or her name and address and the name and address of the owner of such vehicle, or for such person to give a false name and address, and it is likewise unlawful for any such person to refuse or neglect to stop when signaled to stop by any police officer or to refuse upon demand of such police officer to produce his or her certificate of license registration of such vehicle, his or her insurance identification card, or his or her vehicle driver's license or to refuse to permit such officer to take any such license, card, or certificate for the purpose of examination thereof or to refuse to permit the examination of any equipment of such vehicle or the weighing of such vehicle or to refuse or neglect to produce the certificate of license registration of such vehicle, insurance card, or his or her vehicle driver's license when requested by any court. Any police officer shall on request produce evidence of his or her authorization as such. There is no law that says "you have to provide ID only if accused of a crime", or "police can pull you over only if you are suspected of a crime". Various traffic infractions will get you pulled over but are not crimes; random sobriety checks are legal. However, note that the requirement to provide ID applies to the operator. There is no law requiring citizens to carry identification papers (but there is a law requiring a vehicle operator to carry a specific form of ID). In some states there are "stop and identify" laws which allow police to demand ID from a person suspected of a crime, but Washington does not have such a law.
The part about "If I'm the owner of the content, surely I have the right to request its deletion" is the problem. Sure, you have the right to request, but you can't legally compel. You have an agreement with them, according to which you got something, and they got something. You can't then take back the thing that you gave them, which is permission to use. You didn't give them the IP itself, which you still hold. Here's an analogy. You may own a car, and can give a person permission to use the car (let's say "if you bring me back a pound of cheese from the store"). You cannot later change your mind (especially after you've gotten the cheese) a say that you retract that permission and therefore they actually stole your car. When permission to use is given, as long as the conditions for granting permission are satisfied, you can't un-give permission.
Yes, you may call a defendant as a witness and compel the defendant to testify in a civil case. If you need this testimony to prove your case, you should have the clerk issue a subpoena for trial to the defendant and have that subpoena personally served by a process server upon that defendant (sometimes a witness fee, a mileage allowance, and a copy of the relevant statute must also be included in the package). There should be a standard court form available to do this. The subpoena to appear and testify at trial must be delivered to the defendant by the process server a certain amount of time in advance (usually two days, but court rules vary). Also, when you call a defendant as a witness you may generally examine the witness with leading questions, which is something that you are not usually allowed to do with witnesses that you call in your own case. Forcing a defendant to testify to the indisputable facts is a good way to meet your burden of proof towards establishing those facts. But, when you call a defendant as a witness, you should limit your questions to those you know the answer to and can ideally prove with other evidence if the defendant lies. Don't try to tell the entire story of the case with the defendant, just the undisputed facts. The one narrow exception to this would be a criminal contempt of court proceeding (i.e. one seeking the remedy of throwing the offending party in jail where there is no way to obtain relief by taking the action requested) prosecuted by a party within a civil case, to which 5th Amendment protections would apply. But, this would not apply to the kind of case described in the original post.
Keep in mind that a warrant doesn't require proof that you stole the property or have the property. Instead, the warrant is just authorization to look for that proof. The standard for securing a warrant is probable cause, which is a much lower bar to clear than people seem to think. It just requires that given everything the officer knows, there's a "substantial probability" that a piece of evidence will be in a given place at a given time. If the officer swore to a judge that a reliable source had told him that the letter was stolen, then seen in your front yard, and not seen since, I wouldn't be at all surprised if the judge gave him a search warrant.
In US law, there was, as far as the question indicates, no probable cause to search her phone at all, Therefore (unless there is some cause not mentioned in the question), any such search is illegal, and any evidence found in such a search, or that is found as an indirect result of such a search (pointers toward it are found in the search, and followed) would not be admissible in any criminal case against Alice. In the case of Bob, if his friends and family approach the police or other authority with a vague suspicion that Bob might be involved in the creation of illegal content That will probably not constitute probable cause for an arrest of Bob or a search warrant for his phone. Unless the accusation does prove to constitute probable cause, any evidence found during such a search would not be admissible against Bob in a criminal case. In practice, most US police would not undertake either search without better evidence than is described in the question. But some police will overstep the lines, which is what the US exclusionary rule is for. Legal procedure does not as far as I know make a distinction between "exploratory" and "confirmatory" evidence. Instead, evidence is either admissible or not. The rules for when evidence is admissible are quite complex, and vary by jurisdiction. Some of them are more traditional than logical, and some of them are addressed to particular problems that have arisen in particular circumstances. But the US Fourth Amendment protections against unreasonable searches, and the requirement of probable cause before search or arrest warrants are issued, serves some of the same purpose. Other countries have different rules, but many of them restrict the authorities to some extent from making arbitrary searches with no initial evidence. Response to the Revised Question As the question has been edited, there seems to be fairly clear probable cause to search Alice's phone, and if clear evidence of "illegal pornographic content" presumably actually child pornography, as no other kind is illegal simply to posses) is found, she can be brought to trial and perhaps convicted. The mere "suspicion" of Alice's "friends and relatives" would add little and mi8ght well not even be admissible. The facts, if any, on which those suspicions are based might be admissible, one cannot tell from the summary in the question. The case against Bob, however, remains weak. Indeed there still seems to be no probable cause either to arrest Bob nor to se3arch his phone, and the results of any search that was done would not be admissible. Probably none would be done without more evidence. The OP wrote: Thus, although the situation looks grim for both, since the evidence against Bob is confirmatory, it might be considered stronger. Not so, the case against Bob is weaker, indeed so weak that an arrest would be unlikely, and if one were made, the case would likely be dismissed before going to trial, assuming no more evidence than was included inn the question. The evidence prior to the search seems to consist only of vague suspicion not supported by any actual evidence, and so there is nothing to confirm, and no valid search would occur. That suspicion of Bob came before the search, and the search is thus "confirmatory" is not relevant. The question is, what evidence against each defendant is admissible, and does the totality of the admissible evidence amount to "proof beyond a reasonable doubt" no matter what order it was discovered in, or what idea was in the minds of the investigators, provided that they were acting lawfully so that their findings are admissible.
In the USA communication between an attorney and their client is "privileged". This makes it illegal for, amongst other things, the police to listen in to conferences between a suspect and their attorney. However in practice there is often little to prevent the police actually doing so.