The placement of geocaches has occasional critics among some government personnel and the public at large who consider it littering. Some geocachers act to mitigate this perception by picking up litter while they search for geocaches, a practice referred to in the community as "Cache In Trash Out". Events and caches are often organized revolving around this practice, with many areas seeing significant cleanup that would otherwise not take place, or would instead require federal, state or local funds to accomplish. Geocachers are also encouraged to clean up after themselves by retrieving old containers once a cache has been removed from play.