That's why its been encourage to join on reputable campaign managers since mostly they already escrowed the amouny intended for bounty so its gives us little security while doing effort on the camp but don't expect that you be paid on your efforts since sometimes even if the camp pays still there are times that their distributed tokens doesn't get any value.
Out of the thousands of bounties that get posted here, very few end up as escrowed and when one does, there is a huge flock hunters jumping into it. Reputable bounty manager does not equal to an escrowed bounty tokens but of course most managers usually declare that before posting it.
Thats why don't put all your hopes that you will paid but instead treat this as hobby and lucky if will be paid.
True that, most bounty hunters think of this as a job when it is defenitely not so. It is a hit and run/gamble as to which new altcoin will become big. Now bounty hunters cant complain of the same since nobody forced them to join and there was no clause to protect them on non-payment. Thats why I suggest every newbie to get to know this forum and how it works first and then gradually rank up to join a bitcoin payment campaign.
One of the biggest problems is that many teams claim they would have legitimate reasons to stay anonymous. Since that might even be true in some cases, usually it is not but just for the sake of scamming people. It is just hard to differentiate one group from the other. Hence it is a gamble, but sticking with reputable bounty managers helps a bit because you know that they do a good bit of due diligence on their own because they don't want to put their reputation on the line for a blatantly obvious scam.