Prompted by Are digitally signed documents legally binding? - to which the only answer I can give is "It depends on your jurisdiction!", and related to Are employment law questions off-topic?: do we want to consider all questions of law/legality off-topic?
Over on Server Fault we have explicitly disallowed them in our FAQ, being that the vast majority of us aren't lawyers and the wide variation in legal jurisdictions even just within the US makes the questions hard to answer.