It really is. I can't believe who it suggests for me sometimes. A guy I went out with one 6 years ago, that I have zero friends in common with?! HOW does it know this?!
I'm around to write a blog post on this stuff. I noticed it's the new married man's creeping tactic. Two of my married contacts have creeped on my via LI lately. I bet their wives check their fb but not their LI
I think it also gets into your google searches. Like say if someone google searches you, finds your LI profile and clicks on it than it will suggest that person to you as a friend. This is how I figured it suggested my ex-bf to me.