1. The power company (very likely) already knows your power consumption habits. Lots of meters send automated reads every 15 minutes anyway. This is not new, at all. The processing power and manpower to actually mine this data does not yet exist, and if power companies wanted to put this in the pipeline they'd have to spend bazillions of dollars doing so.
2. The EM radiation emitted by smart meters (especially those in the 900MHz range) is comparable to a cell phone, except for the fact that it's not placed directly against your ear, and it chirps for a few ms every few minutes, as opposed to constantly against your head
The crazies who spout nonsense about cancer and privacy are of the same sort that believe in homeopathy. You will notice that they don't cite their sources, and make generalized, unsupported claims.