Is NSA surveillance program limited to Verizon phone calls?

According to a report by Glenn Greenwald in the U.K. Guardian, the NSA has been collecting phone call records of millions of Verizon users.

Many Twitter users suspect that other telecom carriers have been providing records to NSA, too.

https://twitter.com/wheelb/status/342487720259629058

https://twitter.com/WiredPig/status/342465382830968832

The sad irony of the #NSA news is that Verizon is the only one we know about. This has probably happened with all mobile carriers.

— SilenceIsFoo (@SilenceIsFoo) June 6, 2013

•• Obama Secretly Ordered NSA to harvest ALL data from Verizon •• http://t.co/J1IAJZZxbG
(Likely from ALL Carriers)

— Ed Shahzade (@Ed) June 6, 2013

Is the NSA also collecting other forms of communication? Some Twitter users think so:

Good piece by @AdamSerwer wrt the NSA, Verizon & surely other carriers (and other means of communication): http://t.co/S2wajslUvh

— just disgusted (@404errorsgalore) June 6, 2013

https://twitter.com/FloridaLegal/status/342489645134778368

Man, who's the unlucky sod at DOJ who gets to go wading through Glenn Greenwald's emails tonight? http://t.co/ziAqhv4NHv

— Nolan Hicks ? (@ndhapple) June 6, 2013

https://twitter.com/LesNessmanWKRP/status/342487543289352192

#NSA –> private emails, Google searches, parking receipts, travel itineraries, bookstore purchases, and other digital “pocket litter.”

— BUCKEYEinstein (@BUCKEYEinstein) June 6, 2013