All the telcos collect this data as far as I know. They're allowed to for the purposes of improving and maintaining their network. A few crunch it for marketing

All the telcos collect this data as far as I know. They're allowed to for the purposes of improving and maintaining their network. A few crunch it for marketing purposes but this has to be opt-in (not that customers would have any idea what that might entail, even if the privacy policy describes it broadly). I can't comment on the legality of the project I worked on, but I assume it was checked out by legal counsel. I personally wouldn't want my data mined in this way. I don't retain any brand loyalty, lets put it that way.