The Most Notorious And Violent Gangs That Keep The FBI Up At Night
According to the FBI National Gang Report

Currently there are over 1.4 million American citizens claiming gangster status as a fashion accessory, as part of over 33,000 nationwide gangs. Gangs are responsible for 48% of America’s violent crime statistics and are only becoming increasingly dangerous.
Even more worryingly, there seems to be a growing trend of major gang members affiliating with the US military to source weapons and training. The latest federal National Gang Report, published in 2013, was pretty consistent with these figures. The following are some of the most notorious street and prison gangs the FBI are racking their brains to try and dismantle.
The 18th Street Gang

Notably the biggest street gang in California, the 18th Street set is one of the most well known "Sureño" gangs in Southern California. The set has approximately 15,000 members across 32 states and are rapidly gaining further influence. Their crimes range from murder, extortion, alien smuggling, robbery and assault; to drug trafficking, car-jacking and infiltrating the military.
Florencia 13

Are another "Sureño" gang in Southern Los Angeles and a vocal rival of the 18th street clique. They have been linked to the Mexican Mafia and also have been known to purchase weapons from the military. Their influence extends to Virginia and Iowa and they have stacked up charges for piracy, conspiracy to sell drugs, homicide and infiltrating the military.
Barrio Azteca

Based in El Paso, TX, this network of gangsters has been linked to Mexican drug traffickers and is a powerful force on both sides of the border. They tend to recruit new members from Texas prisons and use incarcerated members to produce heroin. Murdering consulate officials, drug dealing and smuggling aliens are there crimes of choice, using a military-like structure to maintain order.
Juggalos

This group of offenders has been in the press for the last few years during their court proceedings with the FBI, as they are suing them for the defamation caused by their placement on the official gang list. Horror-core rap duo Insane Clown Posse (ICP) are demanding that the Juggalos are removed from the list, as their fans are being continually profiled for their distinctive clown makeup and hatchetman tattoos, despite the lack of an obvious link between the ‘gang’ and serious organized crime.
The FBI’s gang list has had a major impact on the fan turnout at their concerts, as they are scared of prosecution. They are only recognised as a gang in four states, due to their loose structure and unclear motive. Most of their offences have been low-level, including drug possession and theft. But the FBI believes there is a link between fans and organized subsets, who have committed felony assaults, theft, robberies and drug sales.
Almighty Latin King Nation

Formed in Chicago in the 1940s, the Latin Kings are now the largest Hispanic street gang in the USA. Their reach crosses 34 states, with an estimated 18,000 members in Chicago alone. They have a separate set in the east coast, but share common values and the religious aesthetic of the gang. Members aim to be reborn as a New King, enlightened and ready to serve the needs of the underdog. The FBI has continually tried to restrict the King’s growing influence and the recent conviction of Augustin ‘Tino’ Zambrano has contributed to their goal.
Somali Gangs

Due to the underlying tension between Somali immigrants and the other African-American gangs, the Somali gangsters have formed their own sets. The Somali gangs have influence in Minnesota, Washington and Missouri, committing alien smuggling, human trafficking, credit card fraud, prostitution and other violent crime.
MS-13 (Mara Salvatrucha)

On the danger scale, this gang hits the number one spot on the FBI’s most wanted list. They began in El Salvador, before reaching transnational levels, with members in 42 states, Guatemala and Mexico. In the past they have been known to work with drug cartels and to have constant communication with their incarcerated members. Despite their lack of leadership, the gang has had multiple well-documented cases of merciless assault. They even have their own task force within the FBI to help take them down and spread awareness.
The Trinitarios

This predominantly Dominican gang is one of the fastest growing sets in New York, with reach in all five boroughs and at least ten other states. They began as a prison gang in the 1980s and are notoriously violent. Their high-profile rivals include; bloods, crips and DDP (Dominicans Don’t Play). They tend to use high schools as their recruitment grounds and are responsible for many teen shootings and machete deaths.
Hermanos De Pistoleros Latinos

This Texas prison gang also has ties with the Mexican drug trade and can be identified through their life-sized handgun tattoos, placed above their trouser lines. They are highly organised, with their own constitution, traditions and life-long membership. Their leader, Jesus Espinosa, is currently serving life for drug trafficking. They are known for their cocaine and cannabis imports and sales, but also meddle in armed burglary, auto-theft, prison gambling, protection rackets, inmate assaults, staff intimidation and murder.
The Mexican Mafia

Officially the oldest and most powerful prison gang in America, the Mexican Mafia unites all the Latino gangsters in the Southern California prison system. Since its formation in the 1950s, the mafia also has influence in Arizona, New Mexico and Texas. Power is delegated among hundreds of inmates across these states, with the ability to command murders of the guards and their enemies, both inside and outside of prison. They also run a drug trade and rackets within prison and some members have even infiltrated the military.
The Mongols

This outlaw biker gang was formed by a group of Hispanic Vietnam war veterans, who were denied membership to the Hells Angels. They are currently present in fourteen US states and have international branches in Australia, Germany, Italy, Mexico and parts of Scandinavia. They are allies with the likes of the Bandidos, Outlaws and the Sons of Silence and tend to make their violent rival wars very public affairs. In 2008 the FBI made 61 arrests for instances of racketeering, murder, drug trafficking and money laundering. Guns, knives, brass knuckles, pipes and steel-toed boots are the crew’s weapons of choice.
The Vagos Motorcycle Club

Otherwise known as "The Psychos"; this club is active across Southern California producing and selling narcotics, possessing weapons and engaging in assault, extortion, theft, money laundering, witness intimidation and insurance fraud. They are military trained and have openly declared war on law enforcement, as well as their rival gang Hells Angels.
Wheels of Soul

This biker clique is predominantly black and is based in Philadelphia. They are presently active in at least six other states and encourage their members to progress to "1%er" or "Diamond" status, through particularly cruel initiation acts. They have previously been charged with a series of robberies and kidnappings and they also produce and sell drugs.