If you go to a political event your smart phone will be scanned and your GPS data will be collected. It's called "geo-fencing" and campaigns use it to better target ads to potential voters.
Texas political consultant Lillian Salerno says you can't really opt out.
"There's not a lot you can do about it at this point unless you're willing to leave your phone at home and most of aren't willing to do that."
Salerno says young voters know the privacy ship has sailed and when older voters find out about it, they mostly shrug.
"It may make people aware; I don't think it's going to make them angry necessarily -- but I may be wrong."
Salerno says campaigns want to know where you live, where you go -- churches, gun clubs, et cetera -- to make sure you're the kind of voter they should go after with their ads.
"Do you got to church, do you go to Wal-Mart, what section of town do you live in? If you're my kind of voter and I feel like you're gonna vote for my candidate I'm gonna make sure I get Facebook ads in front of you; I'm gonna make sure that I message according to what I think your value system is."
Salerno says privacy is a thing of the past when you carry a smart phone. She says you can leave your phone at home or use a flip-phone, but most of us aren't willing to do that.