According to Microsoft Services Agreement, a user must log in to their Microsoft email accounts "periodically, at a minimum of every 270 days , to keep the Microsoft branded services portion of the services active."
If a user does not do so Microsoft states, "we may cancel your access," and "your data may be permanently deleted form our servers."
In an article by PC World it was revealed that Microsoft is now not only closing down old accounts but recycling them. A point which isn't outlined in their policy.
After a total of 360 days, the email account is reissued and made available for anyone to sign up for the chosen name.
This policy feature was confirmed in an email statement from Microsoft.
Yahoo has also been guilty of such actions and has received criticism that it could be classed as a security breach.
Mike Rispoli, Communications Manager at Privacy International, spoke to PC World to say, "Microsoft should absolutely mention this policy in their service agreement. Users should be made aware of this."
Microsoft did not confirm whether they would be adding a section to the online service agreement but have said they "listen closely to the feedback we receive from customers."
Earlier this year Microsoft received a fine from the EU for failing to offer consumers a choice of web browsers when they logged into Windows.
Source: PC World