Anthony Weiner's phone sex partner Sydney Leathers targeted men on the Internet for more than 3 years -- actively recruiting (and juggling) multiple sugar daddies who paid up to $4,000 a pop to connect with her ... TMZ has learned.
We found proof of Sydney's man-hunting history on a hookup site called SeekingArrangement.com ... where she described herself as a 22-year-old "naughty but nice" student.
Best of all ... she proudly announced she's "looking for a discreet, mutually beneficial relationship" ... aka a "sugar daddy."
Sources close to Sydney tell TMZ she's been trolling these kinds of sites since she was 19, and suckers guys would give her anywhere from $200 to $4k to chat, Skype, share pics or meet for dinner.
We're told Sydney claims she never had more than three at once, and never took money for sex. Translation: she never quite went pro.
She told Howard Stern she never got money from Weiner, but admitted she has a knack for finding victims dates.
Sydney's profile lists her body type as "slim."
It was created a year ago ... and is no longer active.