Seems like the kind of thing someone should go to jail for. You can't just run a "social experiment" by committing fraud and lying to people, and that's assuming this isn't just an excuse someone came up with once they knew they would be caught.
It isn’t necessarily a crime to lie or do a hoax, and a fake poll by itself is probably well within the lines of free speech. The fraud question comes into it for two possible cases:
1) someone might have paid them to do a real poll and they faked it, which is just straightforward fraud with a clear victim.
2) (the fun one) they might have done it to manipulate political prediction markets, which gets into securities fraud questions.
It isn’t necessarily a crime to lie or do a hoax, and a fake poll by itself is probably well within the lines of free speech. The fraud question comes into it for two possible cases:
1) someone might have paid them to do a real poll and they faked it, which is just straightforward fraud with a clear victim.
2) (the fun one) they might have done it to manipulate political prediction markets, which gets into securities fraud questions.