I don't know why, but it seems like every day I log on here to see if there are any interesting questions to ponder, and another new user is frantically asking a question about what the exposure is for sexting a minor across international lines. Can there just be a blanket policy that these kind of questions get automatically taken down, even if phrased as a 'hypothetical?'
If it's the same sort of question you should VTC as "Duplicate" (and reference any of the other questions, closed or otherwise).
If it seems to be the same person asking the same question, or using different accounts to circumvent a closure or question ban, then you can flag it and note that (point to at least one of the other questions and/or accounts) so a moderator can ban/delete/merge or even IP-ban as appropriate.
If the question involves significantly different aspects of such a situation than previous questions did, and is not asking for specific legal advice, it should be left open. As Feetwet says, if it is a duplicate, it can be marked and closed as such. If it is a RSLA it should ideally be rewritten to be on topic, but it can also be closed until and unless so re-written.
I am not in favour of this suggestion.
Sexting in itself is not unlawful, it only (mainly) becomes so when it involves children, so a blanket ban may prevent legitimate questions being asked by those purely curious about legal theory or wishing to pose hypertheticals for any number of innocent - and lawful - reasons.
Instead I prefer the current policing by self-regulation being practiced which, in my opinion, works perfectly well in weeding out posts via down votes, VTC or raising helpful flags.
A search of LawSE reveals there have been four questions this calendar year containing "sext" out of a grand total of 17 questions since May 2015, so we are not really experiencing a deluge.
I echo Iñaki Viggers' observations about spiralling blanket bans, and surmise there may more than 17 questions about other potentially unlawful activities so why not ban these as well?
Can we just have a blanket policy that these kind of questions get automatically taken down, even if phrased as a 'hypothetical?'
I personally distrust and altogether skip questions related to child pornography and sex involving minors. I sense those questions to be some people's attempt to know their way around a topic that is plain repugnant. But implementing a blanket policy for this could start up a spiral of automated blanket policies for truly edifying topics.
If you perceive someone "is frantically asking [...] about what the exposure is", tipping Law Enforcement would be more effective.