Thank you, some ann designers are also posting ANN of their clients in their behalf specially if client has no bitcointalk account.
That's fine and not against the forum rules.
But how the hell we will know if a sheep who come to us for service is actually a wolf?
The same way you choose clients in real life. You do the basic research. If you doubt the legitimacy of a job, you simply reject it. It’s not worth putting your reputation at stake for a few bucks.
Are you goin to report them if you found one ico in their portfolio is a scam?
Definitely yes. Anyone can make a mistake in their assessment. What matters is your reaction after it is pointed out to you. Anyone who continues to promote scam projects, even after being pointed to it, should be red-tagged by DT members. How else will other forum members be alerted to scam projects? Not everyone reads the Scam Accusations board.
As @pilosopotasyo commented, your mistake is that you made the thread moderated and you did not address the issue immediately. Would you even remove the ANN post if you didn’t get a negative trust? I guess we'll never know.