I don't know because I don't have the same problems (I make few posts on Google+ and receive even fewer comments when I do), but presumably, all the smart guys

I don't know because I don't have the same problems (I make few posts on Google+ and receive even fewer comments when I do), but presumably, all the smart guys and girls already have each other circled and just ignore all the spam. I can't imagine Linus would even use Google+ if there wasn't an easy method of filtering the wheat from the chaff.