Facebook etiquette question: How do you stop someone from mining your friends?

About a year ago, my sister’s ex-boyfriend found me on FB and during the course of that time, has gone through and ‘friended’ everyone in my network that he thought looked interesting, even though they have never met. He then started manically posting hundreds of things on their sites and mining their friends. I let it slide and figured my friends would just handle him, but now it’s getting to be a lot of people, the connections are really inappropriate and it’s really awkward.

He’s added my co-workers, my ex’s new girlfriend, and a bunch of other people he has no business adding. I’ve asked him not to do it before explaining that it feels invasive and that he doesn’t understand the social relationships, but he’s just defensive and argues back.

How do I politely reiterate in a way that he understands, that it’s not okay to do this, it’s creating uncomfortable situations for me and he needs to back off? Plus, the people he’s connecting with think he’s acting oddly and are irritated by his behavior.