>>1272584081. Post-Crisis Jason is a homeless street kid who took care of his dying drug-addicted mom while his dad was in and out of prison.
2. For some reason, he didn't want to go into the system. When Batman did put him in the system, the orphanage turned out to be using kids as thieves. So child services in Gotham were apparently corrupt and exploitative.
3. DC played with the idea of doing an HIV storyline back in the 80s. According to Wikipedia, Starlin was apparently really really really eager for it to be Robin Jason. Starlin may have been setting up for it, though DC eventually dropped it.
4. Robin Jason got really dark and violent about sex crimes. He possibly pushed a known serial rapist off a balcony, "A Death in the Family" opens with Robin being violently unhinged because of a "kiddie porn ring", and he approved of a woman killing the man who got off the hook for raping and murdering her sister. For some reason, the writers gave these particular storylines to Robin.
5. In a Green Arrow crossover, Red Hood made a beeline for Mia Dearden, who used to be a homeless child prostitute, and started monologuing about how similar they were, and how they both had to do "the bad thing" to get by.
6. At the beginning of the DickBats era, Bruce's video urges Jason to get help and see a doctor about a "dark secret" in Jason's past. Whatever that dark secret is, Jason freaks out when Dick throws the video in his face.
The evidence isn't conclusive, but it's kinda convincing all lined up like that imo.
Even if the implied trafficked kid backstory was a real thing, it was probably erased by Flashpoint and Lobdell. DC probably wouldn't handle that kind of topic well anyway. Then again, people love Guts from Berserk, so who knows?