I have been a victim of bad heir hunters, and I know that Neil Fraser from F & F agrees with me, that the heir hunting industry needs better regulation. In my case, my half-brother's estate was paid out to distant cousins, because the heir hunting company that dealt with it completely failed to find my sister or myself, even though my half-brother's birth certificate clearly showed the name of our father, and my sister's name was on our father's death certificate, as his daughter ! The whole case could have easily have been solved in about 10 minutes by most of the people on this forum !
The difficulty arises because it is hard to prove that the failure to find the correct heirs were due to an intent to deceive and not incompetence. The reason I say this is because although my sister & I were not close to our half-brother (it's quite hard to be close to an almost total recluse who doesn't own a phone and who doesn't reply to letters), but if anyone had knocked on either mine or my sister's door and told us that someone had died and left us money, there was only one person that it could be. The cousins, on the other hand, had never met our half-brother, so they would sign up on the dotted line.
Fortunately for us, the 'wrong heirs' had taken out missing beneficiary insurance, so we got money from that, but we still had to pay legal fees, so we ended up losing 1000's of pounds, and it still took us more than a year to get the money that was rightfully ours. Still, it was still better than having to sue an old lady in her 80's, and creating animosity with cousins that I'd never met. However, if we had gone down that route, I would have also gone after the heir hunting company and had my day in court with them, even though (as Neil Fraser advised) it was highly probable that this small company would probably have gone bankrupt before we saw any damages from them, even if we had managed to prove the case. I will be eternally grateful to Neil Fraser for the time and advice that he gave, even though his company had nothing to do with our case.
If I were to be doing heir hunting professionally, I'd want to take out some sort of insurance in case a mistake ended up as a court case.