Evans, an outreach worker for Positive Health Project, an advocacy group that strives to reduce the spread of H.I.V., was not looking to do drugs. It was a Saturday night, and with more than 900 men logged onto the sex site, he had no problem finding his quarry: a 25-year-old man nicknamed 'Bronxplayer' who was looking to 'party-n-play,' cyberspace lingo for engaging in a sexual encounter enhanced with crystal methamphetamine. Terry Evans turned on the computer, punched in his password and set out on the prowl.
