Subscribers to the world famous magazine and portal Wall Street Journal received an email from the Dow Jones CEO, the owner of WSJ. In the letter, William Lewis is informing the subscribers that their data may have been the target of hacker attacks.

WSJ has, in fact, recently discovered unauthorized intrusions into their computer system, despite all security measures they had implemented. The company immediately upon discovery, prevented these hacker intrusions, and found no direct evidence of theft of any data.

The attacks took place between August 2012 and July 2015.

The investigation showed that a stranger had approached confidential information including address and credit card information for about 3,500 subscribers. Wall Street Journal will send a letter of apology to this group of readers with additional letter with more information and instructions on what to do to protect their privacy.