Extortion, drugs and counterfeit cigarettes are currently their biggest sources of income.
Punishment beatings, arson attacks and threats of violence are how they maintain control.
They mark their territory with sinister murals of masked gunmen and paramilitary flags.
Despite a police operation aimed at cracking down on its criminality, the UVF's grip on many parts of east Belfast remains strong.
Naomi Long, Alliance MP for the area, says several business owners have moved out of the east because of paramilitary influence.
They felt the area's neutrality had been compromised and the neighbourhood was not a friendly place for a mixed workforce, Ms Long said. And then there are the businesses forced to pay "protection money" to the UVF.
Some business owners told the Belfast Telegraph the fee is around £15 a week, but at Christmas and over the July fortnight they must pay a £500 bonus. If they refuse they face the risk of having their business burnt to the ground.
"I sold up and got out. I just got fed up constantly battling with them and being ordered to hand over my money," one former business owner said.
Vast amounts of cash are being made by the gang through drugs. The main ones at the moment are cocaine and marijuana.
It is understood that the number of drug dealers in the area is increasing rapidly, but they only receive a "licence to operate" if they pay the UVF £30 a week.
According to the PSNI, between April and December last year the highest number of cannabis factories discovered by police in Northern Ireland was in east Belfast, where 14 factories were busted. During this period the street value of all seized drugs in the area totalled £298,454.
The gang's criminal operations are overseen by their east Belfast leader, who likes to be known as 'The Beast in the East.'
He is often heard boasting in pubs about being the paramilitary boss after he split from the mainstream terror gang to run his own operation.
The 52-year-old, who is well-known to the authorities, has four deputies to oversee his criminal rackets and act as his debt collectors in Woodstock Road, Newtownards Road, Sydenham and parts of north Down, including the Westwinds estate in Newtownards.
The PSNI insists the paramilitary gang is continually being disrupted.
In 2013, Operation MORS targeted drug dealing and other criminal activity by UVF members in the east of the city and police said there were 175 drug seizures and 115 related arrests in the area last year.
PSNI area commander, Chief Inspector David Moore, said recently that police have been working with the local community to tackle a range of criminality, including drugs, the supply and operation of illegal gaming machines, and the counterfeit cigarette trade.