Out of curiosity (not a real problem): I have a question with 99 votes, now I'm waiting patiently for the 100th vote ;). With the 100th vote a badge will be awarded and I was wondering what happens if the 100th vote gets removed after the badge has been awarded. Will the badge will be removed as well? The help center doesn't give any information about it.
Will the badge will be removed as well?
No for "regular" badges (unless foul play was involved):
In general, if no foul play caused a badge to be awarded (say, a badge for good answer but due to sock-puppet upvotes), even if the conditions that caused a badge to be earned are no longer true, the badge will remain.
We don't revoke badges, unless there was fraud involved in getting them in the first place.
The above is true for "regular" badges - tag badges are a different matter.
Source: Losing a badge in StackOverflow [duplicate], answer by Oded