Missing Coaster Review

I was looking through my coaster uploads and was just wondering what happened to the reviews for my coaster I uploaded a while back.

[url]http://www.coastercrazy.com/track_exchange/detail.asp?tid=2343
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I know there was at least one review becuase I remember them saying somthing about the return run being too slow. I was just curious how a review gets erased.