Running a website that distributes information is not the same as selling drugs. That's why free speech is a right and free drugs are not.

And, yes, there are some types of speech (libel, for instance) that merit special scrutiny. A web forum does not. It is literally just an online conversation—the very definition of protected speech.

For the UK to impose these restrictions within its own borders is already unacceptable. For them to play at imposing them on people in other countries is worse still. If they're serious about this, they should suck it up and proactively block websites from abroad that violate their guidelines. Vague threats of punishments without prior warning are ridiculous.

If I open a store in my home country where I sell goods that are legal (for me) and a citizen of a foreign country travels to me to purchase something that is illegal (for them), I should not be legally liable, no.

Whether that travel happens physically or digitally is of no concern to me.

I suppose you may make the argument that the internet is more like shipping a package than handing something over a counter to a traveler. I don’t think this applies. At most it’s like the customer sends a neutral intermediary to make a purchase/pickup, where that intermediary tells me nothing about the customer except a vague idea of their location (which may be inaccurate). In this case it’s the intermediary, or one of the many intermediaries in the chain, who actually “imports” the item.

If you want to block content, start there with the “importer”. China already understands this well, I don’t know why the UK hasn’t caught on other than a desire to force its own local standards on Americans. We won’t stand for it.

(Your example about forged currency is as absurd as an example about nuclear weapons or attempting to organize revolution. Yes, some things cross the threshold into a critical economic/military issue and all bets are off at that point.)