Yeah I can understand the frustration. Reason for Twitter is identity credibility. I would have added FB as well but this was churned out quite quickly.

Twitter is just as bad at identity credibility as having your own user accounts I would of thought. There are numerous accounts on Twitter with unidentifiable entities?

For egg accounts, sure, but for anyone with > 1,000 tweets, a real photo and > 500 followers, the level of credibility should suffice for most people. What providers would you add in?

Right, so the users can figure out if the user is credible and you don't do it yourself, got a bit confused there.

If users want people to join their groups then they would add their verification regardless, eg register on the site and then in some bio I could add my SO, github etc...