Actually, the worst types do things very blatantly and publicly not in the shadows at all. IMO they do so because they know the SEC does not have adequate resources to go after all the bad guys in the Nasdaq/exchanges let alone the pennies. Chances are very good they will never get caught and can do their thing for many years. If they do happen to get caught, well who cares because they usually just get a slap on the wrist.
BTW, there are different ways of being in trouble. Some here posted their brokers won't even sell them anymore CMKX shares than they currently have because they live in a state where the stock hasn't been registered.