Oh, I don't doubt that. My point was that it's not a universal "Don't Work Here!" message. In our case it seems the staff are happy to put things up like this because they are happy and secure and simply think the strips are funny.

It's the same with all the "629 signs your company is XXX" - they are guidelines, indications, suggestions, and sometimes wrong. There are very few absolutes.

Remember, Bayesian spam filters work because they look for several indicators, good and bad, and combine them. The simply black/white, yes/no indications of whitelists and blacklists don't work as well as taking several indicators into account.