Safety is a concern for sweepstakers just as it is with the general population. This hobby has a higher potential, however, of exposing personal information to spammers and con artists simply because we're often required to give out personal information in order to enter contests. The National Do Not Call Registry can be part of your plan to counter excessive telemarketing.
It's important to read the rules for each sweepstakes you enter, especially in regards to privacy. In the fine print, you may find that by entering the contest you're giving the sponsor permission to call you for other business purposes (sales, surveys, etc.) besides a win. If they do and you inform them you only want to be called in case of a win, that should be that. However, if they continue to call you after the sweepstakes has ended and they don't stop when asked, you may want to report them to the National Do Not Call Registry. There are different time frames involved as your voluntary sweepstakes entry may be considered an 'established' business relationship and they may have a longer time-window in which to comply with do-not-call requests (*see note below).
To get started, go to donotcall.gov. You can register your home phone number and wireless number on the national do-not-call list—up to three numbers—and provide your email. The next step is to verify your registration via a link in an email sent to you by the site. Your number has to be on the registry for 31 days before you can file a complaint against a telemarketer. The complaint will be entered into an FTC database which helps gather information on companies that don't comply with do-not-call requests.
There are organizations that are except from the list such as charities and those of a political nature. More info on that can be found at the site. According to the registry website, scammers have been calling people claiming to be from the registry. The registry will not make unsolicited calls to you, so please don't respond to this scam by giving out your information.
Along with common sense computer and information protection measures such as using a Google Voice number and a separate email for sweepstakes entries, the registry is one more tool to ensure the safety of your personal information.
*For more info on who is exempt from the list and what constitutes an established relationship, visit the consumer information page regarding the National Do Not Call Registry at the Federal Trade Commission's website.