Potential stalker has started to tag my friend in public rants about being rejected (background & history of stalking celebrities in comments)

For about the last five months my friend has been getting daily messages from a guy she knows. They occasionally have to see each other at social events with mutual friends so she thought it would be uncomfortable to block/ delete him only to then see him in person. When the messages first started she would politely respond, but made clear she wasn't interested romantically. She's said she felt bad for him as he seemed lonely and insecure about his partial facial paralysis, but was harmless and just quite socially awkward.

Over time he started to become more and more persistent- until it escalated to the point that he would send her up to a dozen messages a day. He also started posting regularly about how he believed sex work should be legal and posting photos and status' about his frequent sex-tourism trips to Nevada brothels. On top of that, it's become clear he's somewhat unhinged- he's a part-time song writer and does things like send flowers weekly to Ariana Grande's manager, track down and visit the siblings of celebrities he wants to perform his music. He was particularly obsessed with Taylor Swift, who he wrote and recorded numerous ballads about and recently has filed a lawsuit for 'emotional damage' against after her management made it clear that she wasn't open to hearing his music and that his actions bordered on harassment. My friend was further made uncomfortable by the over sexual comments he began writing on her professional modeling pictures (some of which included swimwear and tasteful lingerie). She decided to completely stop responding to him... so he has now started to publicly tag her in posts, subtly slut shaming her for her photos and criticising her for 'not giving her a chance'.

Also side note, all of these posts are from the past month... there are literally thousands like this on his facebook.

/r/creepyPMs Thread Link - imgur.com