Back when I played Ingress, most city-level activity was coordinated through private G+ communities (with neighborhood-level activity being done in Hangouts group chats), and the more social stuff (i.e., the stuff you don't care about keeping secret from the Smurfs) tended to happen in public G+ communities.

LinkedIn is a good tool for viewing someone's public resume, though I don't regularly log into it. Every once in a while, I'll log in to check out how a previous employer is doing (e.g. see which of my ex-coworkers are still at the company, what new positions have been created, etc.). I still have dozens of unanswered connection requests from recruiters, though (I don't accept people I don't know), and the site has gotten progressively spammier over the years.

Did you mean: twitter?

Joking aside I almost never get followed by spam accounts on g+, weekly or more on my English speaking twitter account.