The meme about costumed Toy Story characters at Disney theme parks stopping and dropping to the ground whenever a guest shouts "Andy's coming!" (a reference to how the toy characters in the Toy Story movies behave, going limp and lifeless whenever their owner approaches to cover up the fact that they're "alive") was tested by Temporary Tourist:
Examples: [Collected via e-mail, March 2013]
In a brief interview, a WDW cast member explains that the Toy Story characters used to respond to such signals by stopping and dropping, but the practice has since been discontinued by Disney for safety reasons.
A character attendant at WDW also wrote to tell us:
The characters USED to drop to the ground when someone yelled "Andy's coming." As of the last week or so, however, they no longer do this. This is because EVERYONE found out about it at the same time (when that meme went viral) and now people are shouting this about 50 times per hour and a half, as opposed to hearing it once or twice a day, like before.