I think a lawyer might find a lot of good reasons, even if you could argue that "processing payments" may reasonably take a thousand years.
At this regard there is this thread:
No, if anyone is going to find offences which carry
potential prison sentences (actual criminal prosecutions for AML type offences are pretty rare), it's the regulatory authorities. Users can certainly go that route if they want to, but they need to do so mindful of the fact that they were participating in illegal activity themselves and weigh up whether it's worth the risk of finding their own financial dealings under scrutiny.
From the viewpoint of civil law, "clean hands" might be a sticking point. If the user contracts with GLBSE and the asset issuers are illegal in and of themselves, then civil action to try to enforce them may well be futile.