I've noticed recently that a number of my comments on various questions and answers were deleted. The most recent example is my comment on this question.
The comment contained a quote from Wikipedia and a link to the article there, explicitly answering the question. It was too short to be posted as a full-fledged answer but nevertheless answered the question.
After a couple of days my and few other comments have been deleted, I presume by a moderator. Is there any explanation as to why someone deems it appropriate to censor communications on this site?