Why is not advisable to remove spam links? such as the following:

https://math.stackexchange.com/questions/2896/should-the-constant-pi-be-considered-harmful-closed

I removed the URL but for some reason it has been put back.

And also I noticed that the tag 'pi' has been put back, but I had removed that tag.

• why you consider it spam link, actually?.. btw, revision history says that it was Isaac♦ who did rollback Aug 21, 2010 at 10:37
• (but I hope that question will be deleted) Aug 21, 2010 at 10:52
• I don't think that link is a spam (undiscriminated bulk advertisement). In fact, the link is used as an argument for the OP to consider π harmful. Aug 21, 2010 at 11:24
• Also, why do you want to remove the tag? Aug 21, 2010 at 11:27
• Look here, math.stackexchange.com/questions/tagged/tag-removed tag-removed makes it easier to avoid coming rubbish when you are searching. It's useful to detag these sorts of questions then.
– anon
Aug 21, 2010 at 11:41
• @muad: If you want to avoid closed questions, just add closed:0 to the search term. Aug 21, 2010 at 11:49
• @muad: If this question is so bad that it should not come up in search results for the pi tag, then it should be deleted. But I think that the question, regardless of its quality, is definitely about pi. Aug 21, 2010 at 16:46

As for retagging the question tag-removed, any question that is so bad nobody would want it to come up in their search results is best deleted. For example, a question that is so off-topic it fits no existing tags, and was mistagged by the person who asked it. Vote to delete such questions, or flag them for a moderator to delete.