Yeah, I think it's his own harmless weird humor. Sort of a "hey, I know you're a real person and I know where you work"... which isn't funny to me, but it's an immature "oh look I'm smart and you thought you were private but you're not haha". It's the kind of thing I'd expect out of a devilish 11-12 year old but everybody matures at a different rate. My gut says he's harmless because he's doing it so publicly, as something he finds amusing, but I don't think it's stalker intent, otherwise he would do it privately. If he did it privately and people complained, that'd be different. But being public, it's like a drunk guy at a party who opens his mouth and says something that makes the virtual record needle scratch.