(MONEY Magazine) – Chances are that sometime over the past couple of years a slip of paper appeared in your credit-card statement or your phone bill. Chances are it was labeled something like "dispute resolution." Chances are you either didn't notice it or didn't bother to read it.

That could turn out to be a problem. What was on that slip of paper was a change in your contract with that card issuer or telco. Essentially, it said that you gave up your rights to sue the company in court if you had a dispute. Instead, you had to work it out using binding arbitration, an alternative legal system where professionals (usually lawyers) hear or read evidence and render a decision. And the next time you used that credit card or paid your phone bill, you de facto agreed to those terms.

Steve Tripoli, consumer advocate for the National Consumer Law Center, calls the proliferation of mandatory-arbitration clauses "the single biggest threat to consumer rights in recent years." A decade ago, only one or two credit-card issuers and one HMO had them; today they're in the contracts of all of the top 10 credit-card issuers and most HMOs, as well as the agreements you sign when you take out a student loan or buy a car, computer, health-club membership or pest control contract.

Arbitration isn't new. It started early in the 20th century as a means for businesses to resolve their disputes with one another, and it remained largely a B-to-B option until about a decade ago. That's when companies and their lawyers realized that mandatory-arbitration clauses might be a good way to avoid class-action lawsuits. Plus, arbitration is pricey; according to a report by consumer-rights group Public Citizen--which is disputed by the American Arbitration Association--filing for arbitration is "almost always more expensive" than filing a suit in small-claims court. That means you are less likely to pursue an arbitration claim against your credit-card company over, say, a $29 late-payment fee.

So what can you, the consumer, do?

READ THE FINE PRINT Not all arbitration clauses are bad. The American Arbitration Association, the country's largest such group, has issued a set of consumer protocols--essentially rules of fair play. AAA senior vice president Richard Naimark says that an agreement is fair if it limits the distance you would have to travel for an arbitration; gives you some role in picking the arbitrator; places no limits on your legal rights (such as punitive damages); and limits the fees you'll face. (The AAA caps fees for a $10,000 claim at $125; for claims between $10,000 and $75,000 the cap is $375.)

OPT OUT Because of the increasing media brouhaha about arbitration clauses, some credit-card companies--one is Discover--allow consumers to opt out. The catch: You have to go back to the fine print to know if you have this option.

ASK TO CHOOSE THE ARBITRATOR Even if you're not offered a choice, ask for input. The AAA's fee scale is generally lower than the National Arbitration Forum's. Other groups may charge you for a room and every brief on top of an hourly rate.

FIGHT BACK It's a long shot, but you can try fighting fine print with a little fine print of your own. That's what Margot Rebar of Birmingham did. Back in 2000, she moved into a new house, had a satisfactory termite inspection and signed a maintenance contract with that inspection company. When she discovered both termites and termite damage a few months later, she wanted to sue, but her contract stipulated binding arbitration. So she got crafty. With her next monthly payment, Rebar included her own little slip of paper declaring that she was no longer under binding arbitration. If you disagree, she told the company, let me know. She heard nothing and her check was cashed. And the Alabama Supreme Court sided with her, telling the company that by cashing the check they agreed to a change in the contract. Rebar is now suing for damages. But she admits she already feels victorious.