It's become part of everyday life in the Bay Area -- passing by a homeless drug addict and looking the other way.
But one mother in Livermore is calling on residents to take a good look at the next homeless man you pass on the street because it could be the son she is desperately trying to find.
Jacqueline Berlinn said it's been months since she has seen her son, Corey Sylvester, who is a heroin addict and homeless.
A couple of days ago a photo of him passed out on a BART train popped up on Facebook. Some of the comments were pretty hateful, so Berlinn decided to weigh in and let everyone know that's her son.
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"He's definitely in a lot of pain and he feels bad about who he is right now," Berlinn said in an exclusive interview with NBC Bay Area.
The photo of Sylvester was posted to a Facebook page called "BART Rants and Raves." The page is where BART riders share pictures and videos of bizarre things they see on the train.
"When I find out he's out on the street and I see a picture of him on the BART, that's when I start worrying," brother Christopher Sylvester said. "He's in society now. He has access to drugs."
Berlinn believes her son is one of the nearly 10,000 homeless people living on San Francisco streets.
"It just kept weighing on my mind...I'm going to put a face to who this really is," she said.
Berlinn typed the words "This is my son." She shared an old photo of Sylester when he was sober with the words, "May he return there soon."
"That person is somebody's child and more often than not, they're loved by someone," Berlinn said.
The responses poured in. Most were compassionate and riders typed back that they would keep an eye out for Sylvester.
"Just say a kind word to him. Tell him your mother loves you, she wants you to be healty," Berlinn said.
Berlinn said her church's drug treatment program is offering to help her son beat his addiction again, but he must detox first. She's also taking care of Sylvester's 8-year-old daughter, who Berlinn said is old enough to realize her parents are not around because of drugs.