Erin saw this at CTA headquarters in Chicago. I don't know how they are "servicing" customers, or what kinds of questions are actually ok, but the lady was giving Erin a dirty look for taking the picture, so extrapolate as you will.
I don't usually post the following: newspaper headlines, personal email, craigslist postings, unprofessional websites. I also tend to not crosspost things from other blogs, since I have so much unique material waiting for me to get to it.
Things I see a lot: silica gel "do not eat"; hair dryer labels; inside the bus "do not drill"; Wal-mart sign about IDs; coffee machine with "2" cup sizes; employees must "wash hands".