Bank of America, Citigroup and PNC Financial Services Group are under scrutiny for their use of a mortgage database in foreclosures, Bloomberg reports. MERS is a private database that tracks ownership in about half of U.S. home mortgages. In many cases, banks are using the information from this database instead of original documents to justify foreclosures. Bloomberg reports: It allows banks to buy and sell loans without having to record transfers with the county, and some lenders named MERS as their agent to bring foreclosures. Consumer advocates argue that MERS records aren't a legal substitute for traditional documents, prompting some courts to throw out foreclosures. All three banks made regulatory filings that warn of fines or other penalties if federal regulators rule use of the database is invalid. Citigroup's filing says that MERS is drawing scrutiny from the Justice Department, Congress, Attorneys General and regulators. But, Citigroup "has determined that the integrity of its current foreclosure process is sound." Bank of America also expressed confidence in its use of MERS. PNC said it expects to sign consent orders with regulators for remedial actions on some foreclosures in which MERS was used. "They're recognizing the writing on the wall, that there are serious problems associated with the basic business model and legal theories of the MERS system," said Christopher L. Peterson, a law professor at the University of Utah who has written articles about MERS. Click here to read the rest of Bloomberg's report.