People often try to tag with a sentence, so they'll write something like:
java
upload
problem
...in their tags.
So now there are 56 questions on SO tagged problem
, a completely useless tag.
I suggest this tag should be removed from all questions containing it.
When there's a list of banned tags, this should go on it.
(Fighting the urge to tag this question problem
...)
question
tag.tautology
tag would pretty much cover the lot, don't you think?