So it's a mixed up system from what I hear. Definitely illegal in the UK (Ireland as well, and some other spots in the EU). But there's also places where you can buy it from in the UK online. It's pretty confusing, but you definitely can get in trouble as I've seen people having to go to court over it. I just don't know how rare that is, and I don't think it's really jail time. More of a "pay this fine and you better be on good behavior" situation. Far cry from American laws.