If you're a savvy consumer, you know how small charges can add up over time. You may regularly scrutinize your bank statement for overdraft fees, scan your credit card bill for hidden charges, and pay careful attention to shipping and handling every time you order something online. But you may not realize that unauthorized mystery fees can also hide in your phone bill. Without realizing it, you may be a victim of "cramming," a fraudulent, illegal practice that the FCC is taking action to fight.

Cramming happens when a company puts a charge on your phone bill for a service that you never ordered and almost certainly don't need. Cramming companies don't even need to know your address to place a charge on your bill: They just need to find your phone number online or through a directory. These fake charges can be for services that sound like they're part of your phone service, like long distance service, or they can be for things as diverse as horoscopes, psychic hotlines, or diet plans. When crammers purport to provide a form of telephone service, the FCC generally has jurisdiction to take action against them; when a cramming company bills for an unrelated service, it falls under the Federal Trade Commission's jurisdiction.

Today, the FCC has proposed rules that would help consumers prevent cramming, or detect it and seek redress when it happens. Most phone companies now provide an option that lets consumers block third-party charges - charges from outside companies, including the ones that are the major source of cramming complaints. The trouble is, the phone company may not tell you you have that option unless you come to them with a cramming complaint. Under our proposed rules, phone companies that offer this blocking option would have to tell consumers about it when they sign up for phone service, on their bills and on their websites. This rule would apply to landline phone service, which is the major source of cramming complaints.

Our proposed rules would also require all third-party charges to be separated out from the phone company's charges on landline bills. While our truth-in-billing rules already require that some charges be separated like this, the new proposed rules would strengthen this requirement. And finally, the rules would require both landline and wireless phone companies to give consumers the FCC's complaint contact information on their bills and websites so that consumers can easily come to us with cramming complaints.

Cramming is already one of the most frequent complaints about landline phone bills handled by the FCC. And the complaints we see reflect only a tiny fraction of the problem: An expert study showed that only 5 percent of people who had been charged by one particular crammer were even aware of it.

Today's proposed rules are the second major action the FCC has taken against cramming in the past month. In mid-June, our Enforcement Bureau issued "notices of apparent liability" against four cramming companies, proposing forfeitures totaling $11.7 million. The Bureau's investigation found that consumers all over the country had been victims of these companies. Some consumers were billed more than $400 - the total of many small, bogus charges month after month.

From the states to the federal government, other efforts are also under way to put a stop to cramming. The Senate Commerce Committee is investigating cramming and is expected to hold a hearing in the near future. The Federal Trade Commission, which has jurisdiction over some forms of cramming, is continuing its efforts to fight the problem. And Vermont and Virginia have banned almost all third-party charges (including those from cramming companies) on landline bills.

Take a minute to look at your latest phone bill: Are there any unusual charges you don't understand? If there are, call your carrier and ask for an explanation. If the explanation doesn't satisfy you, you can complain to the FCC now or to the agency in your state that regulates phone companies. Complaints about wireless service or interstate long distance should be filed with the FCC, while complaints about in-state services can be filed with the state. You can also call your landline phone company and ask if it's possible to block third-party charges from your bill altogether.

We'd also like to know what you think about our new proposed rules - you can file a comment on them. And take a minute to comment on this blog and share your story. We're here to help.