Litigation doesn't stop a zombie ticker from trading. Bur for the past couple of months, all kinds of dead stocks have been running for no reason.
For formerly suspended stocks, it has a lot to do with OTC Markets' relatively new Expert Market. While the Expert Market is just the Grey Market by another name, it's different in one important way: the Expert Market has electronic execution.
That makes the stocks much more liquid than they'd be on the Greys.