It's now like a game. 1xBit will come around, offer the shit posters a good amount of money, they will wear their signature and start trolling around. In the current Feedback system I don't think giving red tag is a good practice, but surely we all can leave neutral and alert good projects not to hire them.
Why it's not good practice? Red tag will stop them from joining other campaigns in future and maybe they will think twice before starting to promote 1xbit.
If given a negative feedback to them, sure it will stop them from participating in future signature campaigns (some campaigns still allow negative feedback users) but how and why will the need for them thinking twice will arise when they will not be left capable of promoting any projects later? I agree with Bitcoingirl on a very slight part of giving neutral because there are 'or may be' some good users who will be left a red tag and will have their account's future opportunities seized from them. I would give a negative to the members who took part again in their new campaign but not the newer ones, I will give them one last chance with a neutral. Though, if 1xbit's signature is not needed on the forum, I think admins should step in like they did in yobit's matter and banned them from advertising here.