Here's a new twist on privacy rights: three class action lawsuits charge that Capital One is harming consumers' credit ratings by not reporting their credit limits to the three national credit bureaus -- Equifax, Experian and Trans Union.

The suits, filed in U.S. district court in Greenville, S.C., name the credit bureaus, but not Capital One. They allege that the three credit bureaus violate the federal Fair Credit Reporting Act by not requiring Capital One to report fully on its clients.

Capital One, which has millions of customers nationwide, does not dispute that it withholds customers' credit limits, although it doesn't say why it is so tight-lipped.

There's speculation that Capital One doesn't want to make it easy for competitors to identify its better customers by trolling through the national credit databases.

How does this harm consumers?

Chances are it doesn't make much difference if you're just shopping for a better credit card rate but if you're looking for a mortgage, the effect could be significant.

That's because the dominant credit scoring model -- Fair Isaac Corp.'s FICO score -- looks at a consumer's use of his or her available credit. Without knowing your Capital One credit limit, Fair Isaac can't accurately measure how much of your available credit you're using.

That could be very expensive, possibly costing you a full point, which adds up to many thousands of dollars over the life of a mortage.

Even worse, say the attorneys who filed the suits, most consumers are completely unaware of Capital One's refusal to provide the information Fair Isaac needs, and thus can't do anything to compensate.

Capital One is not alone. Some subprime mortgage lenders don't report any of their clients' on-time payments to the credit bureaus, thereby lowering the positive information in their files and depressing credit scores. Why? The subprime lenders don't want their customers to be able to get a better mortage someplace else.

The law suits do not challenge Capital One's legal right to withhold the information. Instead plaintiff William A. Harris, Sr., charges Equifax, Experian and Trans Union with failure to comply with the Fair Credit Reporting Act.

That law requires the bureaus to follow "reasonable procedures to assure maximum possible accuracy of information in consumer (credit) reports."

Harris' attorneys said the credit bureaus are fully aware that Capital One is withholding information but do nothing to require Capital One and other lenders to provide complete data.