The theft of four computers from Advocate Medical Group last month has now drawn in federal regulators and the Illinois Attorney General's office to investigate, the Chicago Tribune reports. They say the theft of the computers - which contained private information on patients, including social security numbers, is the second largest loss of unsecured protected health information reported to the Department of Health and Human Services since it started requiring notification of such incidents in 2009. Advocate could be fined for not protecting the private health information, but patients could also be at risk of fraud from the thieves. The theft of the unencrypted computers means that information from more than 4 million patients seen by Advocate Medical doctors in either their hospitals or offices since 1990 was taken. The computers were taken from a Park Ridge office, but contain information from anyone who has visited Advocate Medical centers across the region, including in Morton Grove and Niles. The information on the computers includes names, addresses, date of birth and the social security numbers. Full patient medical records were not on the computers, but some medical information was.