So in 1994, a federal law called the Driver's Privacy Protection Act was passed that limits the reasons someone can access your information (stalking and anti-abortion lunacy are not permissible reasons) as well as giving drivers the right to opt out. Unfortunately, since most people aren't even aware that their information is being sold, they don't know to opt out, which usually requires a separate form and isn't prominently advertised. For example, in Michigan, only 70,000 people have opted out since the bill's passage in 1994.
Telemarketers do help pass the lonely hours in Detroit.
If you're in Texas, you're doubly screwed. See, while the federal government threatened to fine states that didn't adopt similar laws, they didn't specify exactly what part of the law would be have to be considered similar. So, Texas created a law that restricted the uses people could buy this information for but didn't give drivers any chance to opt out. And in Florida, the state got around the pesky privacy law by declaring that any information you willingly give to the state for any reason (renting a campsite at a state park, for instance), becomes public information and can be sold.
So if you have any choice in the matter, don't get stalked in the South.