Hack Notice

A 2006 US military study states that:

Hiring a block of bloggers to verbally attack a specific person or promote a specific message may be worth considering.
Hacking the site and subtly changing the messages and data—merely a few words or phrases—may be sufficient to begin destroying the blogger’s credibility with the audience. 

50,000 computer networks were infected with NSA malware
How covert agents infiltrate the Internet to manipulate and deceive