On Wednesday, the group also posted the contact information of Steve Ballmer, Microsoft Corp's retiring chief executive, on its Twitter account along with the message, "You can thank Microsoft for monitoring your accounts/emails using this details. #SEA"

That message was an apparent reference to revelations last year by former National Security Agency contractor Edward Snowden that Skype, which is owned by Microsoft, was part of the NSA's program to monitor communications through some of the biggest US Internet companies.

A message posted on Skype's official Twitter feed on Wednesday, apparently by the hacking group, read: "Don't use Microsoft emails (hotmail, outlook), they are monitoring your accounts and selling the data to the governments. More details soon. #SEA"

Similar messages were posted on Skype's official Facebook pages and on a blog on its website before being taken down in late afternoon. The SEA later tweeted out copies of the message "for those who missed it."

In October, US President Barack Obama’s Twitter and Facebook accounts were hacked and used to promote a video depicting the atrocities committed in Syria by the militants, the Syrian Electronic Army hacker group said.

The Syrian Electronic Army is a hacking group, supporting Syrian President Bashar al-Assad, which became famous in recent month after defacing the websites and Twitter accounts of many prominent media outlets, like AP, AFP, BBC, New York Times and others. 

NTJ/NJF