A key principle on Quora is that Questions are considered to be community property. As such, they can be edited by anyone who can improve them. This also applies to the Question Topics.
Quora users are allowed and encouraged to edit questions to make them better – improving clarity, language, grammar, diction, etc. However, users are not allowed to make edits that are not intended to improve the question; for example, question edits should not be intended to (1) insult the original poster of the question, (2) make a joke, (3) disparage the question itself, or (4) change the meaning of the question. These edits undermine trust in the good faith of the user community and may cause some users to become reluctant to add great content to the site.
Given these concerns, Quora Moderation may decide to quickly warn, edit block, or ban users for malicious question edits.
To report vandalism, see How do I report spam or abuse on Quora?