 Complete the following phrase:  Although small militias had existed throughout the latter half of the 20th century, the groups became more popular during the early 1990s, after a series of standoffs between armed citizens and federal government agents, such as the 1992 Ruby Ridge siege and 1993 Waco Siege. These groups expressed concern for what they perceived as government tyranny within the United States and generally held libertarian and constitutionalist political views, with a strong focus on the Second Amendment gun rights and tax protest. They also embraced many of the same conspiracy theories as predecessor groups on the radical right, particularly the New World Order theory. Currently active examples of such groups are the 3 Percenters and the Oath Keepers. A minority of militia groups, such as Posse Comitatus and the Aryan Nations, were white nationalists and saw militia and patriot movements as a form of white resistance against what they perceived to be a liberal and multiculturalist government. In the 21st century, militia and patriot organizations were notably involved in the 2014 Bundy standoff, the 2016 Occupation of the Malheur National Wildlife Refuge, and in the 