Facebook patented technology on Tuesday that could be used for a number of things. It could help filter out spam email and offensive content. Or it could improve searches.

It could also allow lenders to use a borrower's social network to determine whether he or she is a good credit risk.

Here's how it would work: You apply for a loan and your would-be lender somehow examines the credit ratings of your Facebook friends.

"If the average credit rating of these members is at least a minimum credit score, the lender continues to process the loan application. Otherwise, the loan application is rejected," the patent states.

Facebook (FB) declined to comment.

The company applied for the patent in 2012, after buying it in a bundle of patents from Friendster for $40 million five years ago.

It's not clear if Facebook would ever try to use the patent for lending, or how exactly it would work. How practical is it for a lender to try to access all the necessary information it needs from your Facebook friends?

There is also a federal law, the Equal Credit Opportunity Act, that strictly regulates what criteria creditors can use when deciding on a loan -- things like income, expenses, debts and credit history determine creditworthiness.

"It's nothing to lose sleep over for people with decent credit history, but it could potentially affect those who are borderline to begin with," said Greg McBride, chief financial analyst for Bankrate.com.

The patent was uncovered by Mikhail Avady, founder of SmartUp, a legal technology company in Atlanta.