I have bookmarked, a couple of weeks ago, a top voted question having title Terminal Tips and Tricks For Mac OS X and question id 52483.
Why was it deleted?
It was locked because it was a list-type non-question with link-baiting merit with an SU focus.
List-types are discouraged and closed as off-topic or subjective/argumentative. Any new questions trying to replicate that behaviour will not live though.
But, it was created long ago and linked from a few places with honey dripping from its lips nonetheless.
Locking keeps it alive but does not allow any new content to be added into the mud of its mix.
It's now undeleted.
The question was deleted on 2010-11-24 by Diago♦. It had previously been locked (i.e., basically, made read-only — locking has nothing to do with closing) since 2010-08-05. (Only ♦moderators and ≥10k-rep users can see deleted questions.) I have no idea why the question was deleted. It can still be undeleted by a ♦moderator.
For the time being, the content is still available via the Google cache. When it goes, it will undoubtedly live on on one of the many sites that mirror SU (finally a use for them!). The question is in the data dumps produced before it was deleted.