It was an example. I do not add them anymore. But I get constant notices of random spammers adding me. And these notices show up on every Google page, including normal searches. There is no way Google can tell Mr. X is a friend of a friend or a random social spammer.

Even if you do the right thing, you get those notices. And even if only some of your friends fall for it, it spreads. And I don't blame them, it's a hassle to check.

Edit: and of course, I am not publicly listed! But they can bypass that by adding friends who have their list of contacts public (a default!)