as i said before i understand we need to leave feedback on scammers account and i left negative feedback on OP account. but for the case of signature campaign participants it's a bit of a different case. I agree with leaving neutral and not totally destroying their account. but as already said here, many of the participants have already arrived with negative feedback so it won't make any difference to leave more negative feedback
There is a big difference between green, red and neutral feedback in this forum. Leaving neutral trust could possibly help them go unnoticed by future campaign managers while red trust is difficult to ignore.
Also, there are many 1xbit participants who never had any red trust before joining the campaign which is why it would definitely make a difference. A tough approach is necessary against these shills.