While I don't have any examples right now (because I just went in there to clean the little bastards up, prompting this request), I think we all know there is a problem with new users making tags that shouldn't be tags. Tags like one or an orphaned version number like 2000.
We already have the restriction that low-rep users can't create new tags. I am suggesting tightening that restriction to forbid new users from using tags that have a very low traffic (i.e. the ones that are most likely typos). Alternatively this restriction might only be in place for the very first question a user asks.
One thing I mentioned before in an answer (and am now reiterating as an actual request (linking to Welbog in the process)) is a warning when users are creating new tags and using tags that don't have a lot of traffic. But then again, users who put their titles in the tag field obviously aren't reading instructions in the first place, so why would they read the warnings?
My suggestions in this question are just some of my ideas. I think we should look for more ideas so that we can address this problem properly. Whatever we come up with should make it so that I don't have to spend several agonizing minutes trying to remove stupid tags en masse. Bad tags are distracting, and while I'm trying to answer questions I get off on retagging tangents. I'm sure I'm not the only one who would be more productive if tags, in general, were used a bit more strictly.
Also, it's very difficult for a dismembered head like me to solve those clever visual brain-teasers the robots give us. Though I do share their affinity for Madonna.