You can be sure that the NSA does this all the time.
Check it out:
GCHQ has developed a toolkit of software programs used to manipulate online traffic, infiltrate users’ computers and spread select messages across social media sites including Facebook and YouTube.
The UK spy agency’s dark arts were revealed in documents first published by The Intercept, and each piece of software is described in a wiki document written up by GCHQ’s Joint Threat Research Intelligence Group (JTRIG). The document, which reads like a software inventory, calls the tools part of the agency’s “weaponised capability.”
Some of the most interesting capabilities of the tools on the list include the ability to seed the web with false information — such as tweaking the results of online polls — inflating pageview counts, censoring video content deemed “extremist” and the use of psychological manipulation on targets — something similar to a research project conducted with Facebook’s approval, which resulted in heavy criticism and outrage levied at the social media site.Continue reading on www.zdnet.com