In fairness we're not even really sure what a block does and how the system works. I've seen plenty of requesters move heaven and earth to remove the block. I had one make a $0.50 test hit just to check to make sure I could get back into his hits.It's already been sent and he replied, if the user has no problem blocking people in order to stop them from retaking their underpaid survey... Then it didn't matter what I wrote. He had to be ignorant of what a block does. And if he wasn't, then he's a piece of shit and I'd like to attest to that with passive-aggressive wording.
But the other assumption was I actually did another hit under a different name. In which case, he probably knows how Mturk works.
Plenty of shady requesters around, but lets not assume that they are shady from the start. When we do that we scare away the good ones.