What's the mechanism for stopping them?

Interdiction at the ports. Seizure of persons related to the enterprise crossing into the jurisdiction.

Interdiction at the ports is the buyer's problem, not the seller's. Kidnapping people because of their employer sounds like a great way to lose tourism permanently.

Because the warranty is too short? I'll go with 'no chance' on that one.

Oh yeah, as a practical matter I totally agree though lack of enforcement invites more participation by other actors.