tag system corrupted by too much- or unrelated tags

Bdsmlr have put quite some work in the tag system, and searching with tags. I thank for that. Recently I've noticed that the number of posts with loads of tags, mostly unrelated to the picture are growing. With that all of their effort has become useless. Search comes up with random results because of that.
In the TOS of "the site that I wont mention" there was a clause that stated that tags needed to be related to the post. Is there such a clause in Bdsmlr's TOS? And didn't Tumblr (oops, l said it) only use the first number of tags and disregarded the overload? Maybe that could be a way to overcome the tag chaos that some users have caused.
Pleas poeple only put related tags with your posts, or we remain in this chaos.