That is why you are advised to read all the contents in bounty campaign thread to make you understand the rules, it is your decision to push through or not.
Some People tend to scroll down to the registration link to fill up than reading the entire rules for the sake of their agreement to the bounty, this is a common practice for the bounty for changing rules due to some valid reasons, we encountered projects that abuses that rule but if you are picky with the ICO you will less likely going to encounter such unprofessional team to do such actions against to its advertisers.