> However, CAPTCHAs aren't going away just yet. In cases when the risk analysis engine can't confidently predict whether a user is a human or an abusive agent, it will prompt a CAPTCHA to elicit more cues, increasing the number of security checkpoints to confirm the user is valid.

Probably using a combination of G+ and GA to check your 'history' to see the activity is like a normal human. Visits a couple news sites each day, checks their gmail, searches for random crap randomly, GA registered a 'conversion' for some company = probably a human