From wikipedia, modern day vigilantes:
20th century
In the 1920s, the Big Sword Society of China protected life and property in a state of anarchy.
Formed in 1977, the Sea Shepherd Conservation Society has been increasingly active against whaling and fishing vessels which they see as violating international laws, regulations and treaties, particularly where whaling is concerned. It endorses an active policy of scuttling fishing and whaling vessels while in harbor, and ramming and sinking vessels engaged in the killing of whales. A tally on the side of the Sea Shepherd vessel RV Farley Mowat displays the ten whaling vessels (referred to as "Pirates" by the society) sent to the bottom by Sea Shepherds:
1979 – the whaler Sierra rammed and sunk in Portugal;
1980 – the whalers Isba I and Isba II sunk in Vigo, Spain;
1980 – the whalers Susan and Theresa sunk in South Africa;
1981 – the whaling ships Hvalur 6 and Hvalur 7 sunk in Iceland;
1992 – the whaler Nybraena sunk in Norway;
1994 – the whaler Senet sunk in Norway;
1998 – the whaler Morild sunk in Norway.
Founded in 1979 in New York City, the Guardian Angels is a recognized crime fighting organization that now has chapters in many other cities. It has sometimes been incorrectly called a vigilante organization. Safety Patrol members are instructed to call police, are trained in basic first aid, CPR, law, conflict resolution, communication, and basic martial arts, and are prohibited from carrying weapons.
Recognized since the 1980s, Sombra Negra or "Black Shadow" of El Salvador is a group of mostly retired police officers and military personnel whose sole duty is to cleanse the country of "impure" social elements. Along with several other organizations, Sombra Negra are a remnant of the death squads from the civil war of the 1970s and 1980s.[5]
In 1981, a resident of the rural town Skidmore, Missouri fatally shot town bully Ken McElroy in broad daylight after years of crimes without any punishment. Forty five people witnessed the shooting, but everybody kept quiet when it came time to identify the shooter.
In 1984, Bernhard Goetz entered a subway train in New York and was surrounded by a group. He shot all four, fled the scene, and was called "the subway vigilante" by some media.
Known since 1995, the Davao Death Squad of present-day Davao City, Philippines unleashed a killing spree aimed at the city's (supposed) notorious criminals and children by unknown motorcycle riding vigilantes.
Formed since 1996, the People Against Gangsterism and Drugs of Cape Town, South Africa fights drugs and gangsterism in their region.
Formed since 1998, the Bakassi Boys of Nigeria were viewed as the frontmen in lowering the region's high crime when police were ineffective.
21st century (present day)
Formed since 2000, Ranch Rescue is a still functioning organization in the southwest United States ranchers call upon to forcibly remove illegal aliens and squatters off their property.
In the early decade of 2000, after the September 11 attacks, Jonathan Idema, a self-proclaimed vigilante, entered Afghanistan and captured many people he claimed to be terrorists. Idema claimed he was collaborating with, and supported by, the United States Government. He even sold news-media outlets tapes that he claimed showed an Al Qaeda training camp in action. His operations ended abruptly when he was arrested with his partners in 2004 and sentenced to 10 years in a notorious Afghan prison, before being pardoned in 2007.
Operated since 2002, perverted-justice.com opponents have accused the website of being modern day cyber vigilantes.
In Hampshire, England, during 2006, a vigilante slashed the tyres of more than twenty cars, leaving a note made from cut-out newsprint stating "Warning: you have been seen while using your mobile phone". Driving whilst using a mobile is a criminal offence in the UK, but the law is little observed or enforced.[6]
In Northern Ireland, vigilantism has been observed against drug dealers and pedophiles. In one such case, a known pedophile had been released from prison early, kidnapped by a group of men dressed in black clothing and balaclavas, much like the Provisional Irish Republican Army or Ulster Volunteer Force. He was stabbed twice, then, put in the back of a Ford Transit van where four Bull Mastiff dogs were waiting for him. He was then driven around Belfast and Derry for two hours. After the dogs mauled him, he was dumped in the verges of a dual carriageway. He survived.
In 2007, religious vigilantes in the southern Iraqi city of Basrain warning against "violating Islamic teachings" killed at least 40 women not wearing traditional dress and head scarves.[7]
The Minuteman Project, a group created to deter illegal aliens and drug smugglers from entering the United States, was criticized for making citizen arrests.
A sect of the internet-based group Anonymous has brought down websites of the Church of Scientology in response to their attempts at internet censorship. They have also organized peaceful protests against the organization, calling it a exploitive business and cult, during which almost all members wear masks.