Your personal data is valuable to marketers, which is why so many companies have details about you on their books—all of which can be used to target you with advertising, or to find out where you live and work, or even to steal your identity for fraudulent purposes. The good news is that it's possible to fight back and get yourself delisted from these databases. The bad news? It takes a lot of time and effort.

Still, it's worth at least giving it a try. These services pull from public records and other online sources to build profiles of you that, when compiled in one place, can be used for all kinds of ill effects, from unnervingly targeted marketing to doxxing. Daunting as the task might sound, spending a few hours severing ties with data brokers could make it that much harder for people to cause you harm.

Several of the biggest make opting out relatively easy; just fill out a form and make a couple of clicks. Others go so far as demanding a photo of your driver's license before scrubbing your details. But go ahead and start with the easy ones, and build from there.

For starters, you can potentially head off identity theft associated with info gleaned from data brokers by freezing your credit to prevent new creditors from accessing your credit report. Note that this doesn't stop your credit, but it can help cut down on fraudsters opening new accounts without your knowledge. The fees vary by state, but you can contact the major credit score providers here: contact Equifax at 1 (800) 349-9960, Experian at 1 (888) 397‑3742, TransUnion at 1 (888) 909-8872, or Innovis at 1 (800) 540-2505.

You can also get in touch with each company and agency that has data on you—your state's motor vehicle department, your home and mobile phone companies, and so on. You may be able to request that they hide your details from certain records.

Then there are the centralized services you can use to opt-out more broadly. Register with DMAchoice to get off of direct marketing and telemarking lists. Nuke those prescreened credit offers at the official Consumer Credit Reporting Industry site. And of course there's the Do Not Call Registry—even though it doesn't always work as advertised. If you've been a victim of violent crime or identity theft, it can give you special rights in terms of what you can opt out of, though you may need to provide court orders and other evidence as proof.

Another option is to consider paying for a service that does the legwork for you. DeleteMe charges $129 per year and keeps your data off more than 30 of the biggest data brokers in the business. You then get quarterly updates on the work that the service is doing to restrict the spread of your personal data.

PrivacyDuck is even more comprehensive, but will cost you more as well, starting at $499 per year for two people. It removes you and everyone in your household from 90 data broker databases, and sends you progress reports every month. Just remember that not even these services are comprehensive. PrivacyDuck, for instance, will block your data from 100 additional sites—for $999 a year.

Both DeleteMe and PrivacyDuck also offer free resources for helping you opt out manually from data broker lists, and there are numerous, really good resources on the web as well. Check the master list at StopDataMining.me, or the Big Ass Data Broker Opt-Out List complied by journalist Yael Grauer.

LEARN MORE The WIRED Guide to Personal Data

To help you get started—and to illustrate how onerous the process can be—we've given a few examples of how to opt out of a few specific data brokers below. Yes, it's a pain. No, it might not be possible to shut down every bit of data-scraping across the web, especially when so many of these companies operate completely under the radar. And many of them simply pull from public records, which will always be, well, public. But it's still worth doing what you can to make sure that your Yelp orders stay between you and the restaurant.