The Syrian Electronic Army has reportedly claimed responsibility for hacking the social media accounts of the Internet calling service Skype.
As part of the hacking attempts, the group sent anti-surveillance messages, such as a message notifying individuals not to use email services of Microsoft.
Hackers posted on Skype's Twitter account: "Don't use Microsoft emails (hotmail, outlook). They are monitoring your accounts and selling the data to the governments."
Posting the contact details of Microsoft's retiring CEO Steve Ballmer, hackers said: "You can thank Microsoft for monitoring your accounts/emails using this details. #SEA"
Skype spokesperson said: "We recently became aware of a targeted cyber attack that led to access to Skype's social media properties, but these credentials were quickly reset. No user information was compromised."
In addition, the Syrian Electronics Army posted similar messages on Skype's official Facebook pages in addition to a blog on its website.
The snooping activities of NSA made Microsoft and other tech firms collaborate on government surveillance efforts against private individuals in the US and in several other places.
In December 2013, Microsoft joined seven other tech firms to call for limits on NSA's surveillance activities.