Ok, kinda freaky. Last night I returned from a weekend away to notice iTunes running. Funny, I thought, since I quit everything before I left. Upon trying to quit iTunes, it simply relaunches 2-10 seconds later (the delay varies). Force quit, killall, logouts, and reboots have all failed to resolve this issue. It even auto-launches after reboot.
I generally leave iTunes running with sharing anyway, but perhaps someone installed a cron job on me to keep iTunes open so they could download from me? I'm not getting any sort of message about another user being connected to me when i quit iTunes.
Latest everything (10.3.2, iTunes 4.2).