Cheating in GotW voting?

How easy is it to create many accounts and cheat in girl of the week voting? It looks kinda suspicious sometimes when one of the girls is losing a lot and suddenly gets 20 votes out of the blue.

Should accounts be given voting rights only after they've been active for long enough here?

Can you tell me when you think the cheating took place, and whom the votes were for?

I looked at the current votes and was not able to see obvious signs of cheating.