Sniping generally has one of three causes: the sniper wishes to spite a particular author, they are jealous of others' success, or they just like annoying people. Almost all maps on the now removed top-rated maps listing have been sniped, and very few managed to remain at the top for an extended period.
Many people considered NUMA's lists of top-rated maps and authors extremely inaccurate due to sniping and other forms of voting abuse. With NUMA's redesign, completed on May 25, 2008, these listings were removed, lessening the emphasis on ratings, but sniping remains a problem.
Sniping is very unpopular and newer users often make anti-sniping threads on the Metanet Forums.