Seems like someone previously went through and removed all of those tags.
Thought I should bring this to meta's attention.
I have reverted all the retagging done by this user. The serial upvoting script should catch his expanded privileges (he got super upvoted just a short while ago), and reverse the upvotes, thereby removing his ability to retag questions.
I spent some time while I was at reviewing and fixing some of the questions, too, so they should be a bit neater.
Still definitely not something that should be done, but the end result is (slightly) higher quality content.