Absolutely. Glenn Greenwald is attacked from both the right and left constantly. The Republicans call him a socialist because he's spoken at the Socialism Conference a few times and because he was critical of the Bush administration. Democrats call him a libertarian because he's associated with the Cato Institute and has been critical of the Obama administration. Greenwald has written a really good paper on Portugal and drug decriminalization. [1] I'm assuming it's published by Cato because of the prominence it has on their website.[2], [3] are videos of Glenn Greenwald speaking at Cato conferences. [4] is a video of him doing an interview with Reason.

[1] http://www.cato.org/publications/white-paper/drug-decriminal...

[2] http://www.youtube.com/watch?v=zPok-FIKGgc

[3] http://www.youtube.com/watch?v=PabkB4RnGJQ

[4] http://www.youtube.com/watch?v=kjuvXdqKM0M

Here's some of his articles criticizing the use of the obama administration, use of drones, etc.

- http://www.guardian.co.uk/commentisfree/2013/may/27/obama-wa...

- http://www.salon.com/2012/04/19/americas_drone_sickness/

- http://www.salon.com/2012/04/20/obamas_dismal_civil_libertie...

- Here's a speech of him criticizing Obama's awful civil liberties record http://www.youtube.com/watch?feature=player_embedded&v=rN5Nl...

Without a doubt the Guardian is taking a specific approach to leaking the documents, but I think a big part of it is that they have a lot to process. That's something that Greenwald has continually said on his Twitter feed. I guess what made me so angry about your comment is that it's often used as a smear against Greenwald. Greenwald doesn't prescribe to the left/right paradigm. He is both vilified and exemplified by both the left and right wing media all the time.