What is the history of minors being unable to bind themselves to contracts? What was the first jurisdiction that had special rules for contracts to which a person under a certain age is a party? How did the modern concept that people under 18 can back out of contracts except those for essential products or services develop in English common law?
This was at least a feature of Athenian law. In the Aristarchus of Isaeus (early 4th century BC), it is recorded that &quot;the law expressly forbids any child—or woman—to contract for the disposal of more than a bushel of barley&quot;. This is a sufficiently ancient and transmissible principle of law that there well may have been Egyptian and Sumerian analogs. You might get the details that you seek by focusing on medieval English common law.
Contracts that violate local law are void in just about every jurisdiction, as are contracts against clearly defined public policy. In many cases, laws are specifically designed to restrict otherwise valid contracts; for instance, in the US, an employment contract that pays less than $7.25 an hour will normally be invalid, even if the company and the employee both agree to the reduced wage. In employment law, where contracts are fairly common, the laws would be virtually meaningless if contracts took precedence. In the case of independent contractor status vs. employee status, California law does not consider someone to be an independent contractor just because their contract says so. "Independent contractor" is defined in California law to be any person who renders service for a specified recompense for a specified result, under the control of his principal as to the result of his work only and not as to the means by which such result is accomplished. (California Labor Code, section 3353) If this definition isn't satisfied, it's irrelevant what the parties agree the status is; it's not an independent contractor status. According to the state department of labor, the test is that found in Borello v. Dept. of Industrial Relations (a California Supreme Court case), which lays out a multifactor test for contractor status and says that The label placed by the parties on their relationship is not dispositive, and subterfuges are not countenanced. Likewise, with product liability, a country can generally have laws mandating liability for people providing a product or service; the extent to which this happens depends on the jurisdiction. For instance, India may not want a big company like Uber to be able to block liability claims by putting some legalese in front of average consumers who aren't able to make a detailed risk-benefit analysis. Alternatively, India could decide that Uber is better able to take the risk from bad drivers than average consumers are, so the right policy is to assign the risk to Uber. Whether Uber should be able to avoid liability is something that every country can decide for itself based on public policy considerations; the point is that if they do decide that Uber should be liable for damages, their law trumps Uber's contract. Uber actually tries to limit liability in their EULA, and to avoid an employer-employee relationship in their driver agreement. Their US EULA and driver agreement says they aren't a transportation provider and you aren't getting transportation from them, and even if you are they aren't liable for damages. However, if that provision violates the law in some state, the provision is invalid. Likewise, if they claim it's not an employment contract but it meets the "employee" definition in some state, it's an employment contract.
States have a general police power, meaning that they can pass laws about whatever they want unless there's a specific reason they can't. A state does not have to give special justification for why something is in the realm of stuff they can regulate; someone challenging it has to say what specific section of the Constitution it violates. For a time, the Due Process clause of the US Constitution was considered to imply freedom of contract. This time ended in the 1930s. The doctrine of a constitutionally protected freedom of contract is pretty much completely dead. A state can't abridge the freedom of contract for no reason, but that's because just about any law needs some reason to be allowed. The level of review is that the law is rationally related to a legitimate state interest; this is not a very demanding level of review. Source State bar associations are given power by laws making it illegal to practice law without being a member of the bar and requiring licensed lawyers to comply with bar rules. State bars that control admission to practice are generally government agencies (specifically, agencies of the court system). When the state bar is not a government agency, attorney discipline and licensing is handled by a government agency (lawyers might have to join the bar, but the bar has to accept licensed lawyers as members; the bar's power in these cases is limited to recommendations to the courts).
I was initially going to vote to close this as a political rather than a legal question, however, I think there is scope for separating out the two dimensions. Our society makes a distinction between children and adults by giving them different legal rights, obligations and protections. If you think about it, there are a lot of things beyond sexual activity where the law does this: voting, drinking, military service, compulsory schooling, legal culpability etc. What things are subject to legal restriction is a political distinction. Now, there is no reason politically why these laws could not have been drafted to say "children can do this, adults can do that" and leave it to the courts to decide who is a "child" and who is an "adult". Biologically and emotionally people reach maturity at different ages so this is perfectly sensible. It might even be more just. However, justice is only one thing that we require of our legal system. Among the others are certainty and efficiency. Providing a bright line based on birth date gives certainty. Not requiring the court to deal with this on a case-by-case basis increases efficiency - justice is not free. This is why jurisdictions use age as a proxy for adulthood. As to why they choose any particular age, that is a political question.
The only issue relevant to your age is the (ir)revocability of the license. GPLv3 purports to be an irrevocable license. To be really irrevocable, the license would need to grant certain rights in exchange for something of value, that is, you need a license that passes muster as a contract. Copyright licenses are typically treated as contracts, but it is not clearly established in law that licenses are contracts or are not contracts. Out of the goodness of your heart, you can grant permission to use your property, but you can also withdraw that permission. If you have a contract granting perpetual permission to use your property in exchange for something of value, then you can't later withdraw that permission. In the case of Jacobsen v. Kratzer, the sides advances opposing theories that the license was a "bare license" vs. was a contract. (The matter was ultimately settled out of court). This article puts together the legal factors surrounding the notion of license as contract, see p. 21 ff, and esp. §IV for arguments that licenses should be contracts, to be fully enforceable. A contract for non-essentials formed with a minor is not enforceable, until you are 18. You could therefore revoke the license, until you are 18. Anyone who uses the software does so at their peril. However, if the license is not a contract, no existing legal doctrine (in the US) whereby the permission is irrevocable. In other words, yes you can, at their peril. The whole license-as-contract issue is very complicated, and I'm only focusing on the revocability issue. There is a separate question whether one can sue a user for both copyright infringement and breach of contract. The case of Artifex v. Hancom, see also this analysis, found that (in the particular case), plaintiff can pursue the matter as both infringement and contract breach.
tl;dr It seems like a bad idea. Massachusetts's statutes don't seem to expressly prohibit it—and I didn't find any Massachusetts cases where the registered agent's age was at issue. But registered agents have some fiduciary duties, and the agent has to have the capacity to receive all forms of legal process. Some possible roadblocks are: &quot;minor&quot; is a broad term that courts don't seem to have interpreted in the context of registered agents, and each form of legal process sets its own requirements. Background First, the term &quot;minor&quot; encompasses extremes: a 1 year old doesn't have the capacity to receive and forward legal process to the intended party, but a 16 year old might. Some jurisdictions recognize a &quot;suitable age and discretion&quot; rule, though it hasn't been extended to the context of registered agents. See, e.g., Fed. R. of Civ. Proc. 4(e)(2)(B). Massachusetts isn't one of those jurisdictions. See Mass. R. Civ. Pro. 4(d)(1). In the broader law of agency, minors do have the capacity to serve as &quot;agents&quot;—though their ability to affect the legal relations of the principal is limited. For example, the enforceability of minors' contracts is an issue, and minors can't enter into durable powers of attorney or serve as trustees. See Restatement (Third) of Agency § 3.04. The problems associated with appointing a minor as an agent in Massachusetts are longstanding. In Commonwealth v. O'Leary, 143 Mass. 95 (1886), a mother had her minor daughter enter into a contract of sale for alcohol for the mother's use. While the court recognized the daughter as the mother's agent, it still characterized the transaction as an illegal sale &quot;to&quot; a minor. In the case of a registered agent, the primary action Massachusetts expects of the agent is the receipt and forwarding of the principal's legal correspondence. Courts have found that this creates a fiduciary duty on the registered agent's part. See Int'l Envtl. Mgmt. v. United Corporate Servs., 858 F.3d 1121 (8th Cir. 2017). This makes sense because the service of process satisfies constitutional requirements embodied in the Due Process clause. So in predicting whether a court would extend the &quot;suitable age and discretion&quot; rule to registered agents (or even needs to), it would likely consider that the agent has fiduciary duties, albeit more limited than those of a typical trustee. Second, Mass. Gen. Laws ch. 156B § 49 governs corporations and requires that the agent be capable of receiving &quot;all lawful processes in any action or proceeding&quot;. When the agent is an individual (as opposed to a company), that person must be a resident of Massachusetts and have a &quot;business address in the commonwealth&quot;. Mass. Gen. Laws 156C § 5 governs the process for LLCs, and Mass Gen. Laws 156D § 15.07 details it for non-Massachusetts companies. Massachusetts's statutes don't expressly prohibit minors from serving as registered agents, but the agent must have the capacity to receive all forms of lawful process. Thus if some lawful process requires delivery to an adult, the minor wouldn't be capable of receiving it.
The only age of consent in England and Wales is 16. The relevant provision is Section 9 of the Sexual Offences Act 2003. 9 Sexual activity with a child (1) A person aged 18 or over (A) commits an offence if— (a) he intentionally touches another person (B), (b) the touching is sexual, and (c) either— (i) B is under 16 and A does not reasonably believe that B is 16 or over, or (ii) B is under 13. Sex between your two hypothetical people is always legal as both are aged 16 or older at all times (under this provision - there are a raft of reasons why it may be illegal notwithstanding).
So far as I can see, no US law required an airline to demand written parental consent for a passenger aged 17 in 2004, nor does any law requires such consent now. A passport could probably have been required. Minors in general may make and enforce contracts, including those for purchase of travel services. Parental consent is only required for a few specific activities, and air travel does not seem to be one. The question asks &quot;Was I liable at 17 or 18...?&quot; Liable for what? There is no liability unless there is wrongdoing or negligence or at least harm to someone. I don't see what there was to be liable for here, so there is no reason to try to determine who was liable. Had a law been violated, it would make sense to ask who was criminally responsible, but apparently none was. If no one was harmed there is no civil liability. I am not clear why the OP thinks there was a legal problem. Nothing in the question indicates that there would have been.