A new report released by the San Diego anti-fraud. firm ID Analytics states that one out of every seven social security numbers (SSN) have been stolen, according to MSNBC.

The company analyzed 290 million SSNs and found that approximately 40 million of them were attached to more than one name, suggesting that the private number had been compromised by criminals. Some thieves may be using these numbers to apply for lines of credit.

ID Analytics regularly helps combat fraud. by checking the credit applications they receive from their clients against larger databases. The company reports that some criminals may use evasive tactics, such as applying for credit at several different banks with SSNs that are almost identical.

The report also found that five million of the SSNs are attached to three or more people. While many of these discrepancies may be due to unintentional errors, such as typos, a significant portion are likely due to identity theft, according to the news source.

Many criminals use the internet to obtain personal or private data. According to Microsoft, one way to prevent online ID theft is to use a secure payment company when shopping online.