According to developer Till Schadde, random people may be receiving your AIM messages if you have a jailbroken or unlocked iPhone. In fact, anyone with a jailbroken iPhone may be getting them, according to his testing:
Just found a HUGE #security #hole w/ push & AIM. Someone got my sent messages and wrote back. DO NOT send confidential AIM msg to #iPhone
#iPhone #push #security #hole:my msg was received by an hacked iPhone w/ push service hack; msg seems to be broadcasted to all hacked phones
Take extreme caution when sending AIM msg to people w/ hacked iPhones. Push service broadcasts your msg to strangers. Pls RT
@martinhering there seems to be a brand new hack that reactivates push with the effect that received msg are broadcasted to strangers
Here's a screenshot the random receiver of my msgs sent me back http://twitpic.com/b3bct I used iChat on a Mac #iPhone #push #security #hole
The problem seems a result from a hack to avoid Apple's jailbroken/unlocked iPhone push blockade, so if you haven't used any of this, keep sending your kinky messages to your mistress or master as usual. Otherwise, zip it.