I'm not sure "persecution" is the right word for this, but the DOJ unilaterally seized phone records for several Associated Press journalists directly from the telephone company without notifying the AP first.

Needless to say, this is a gross abuse of power; the AP couldn't even challenge the seizure in court because they executed the seizure secretly. It's particularly frightening because it dissuades anyone, particularly government officials potentially privy to corrupt programs & practices, from anonymously talking to journalists.

http://www.nytimes.com/2013/05/20/business/media/head-of-the...

EDIT: here's a Wikipedia article on the topic: http://en.wikipedia.org/wiki/2013_Department_of_Justice_inve...