These groups may deface websites, redirect traffic, launch denial-of-service attacks and steal information to make their point.
Hacktivist group LulzSec dominated headlines in 2011 with attacks on Sony, PBS, the U.S. Senate, the CIA, FBI affiliate InfraGard and others, and then disbanded after 50 days.
Anonymous, a loosely-affiliated international hacking group, claims that its tactics initiate civil disobedience. For example, Anonymous has been suspected of taking down sites in El Salvador, Israel and the city of Toronto through distributed denial-of-service attacks. Hackers affiliated with the group also released 90,000 email addresses of U.S. military personnel in an attack on Booz Allen Hamilton.
The variety of targets seems to show that almost any institution could be at risk, although only a tiny minority is affected by hacktivist attacks. Significantly, law enforcement organizations have arrested many members of LulzSec and Anonymous.
Encryption is the best way to protect against hackers and unauthorized access of sensitive data.