Dog fighting is illegal in all 50 US states, yes, but then it is both widespread and growing, reports suggest.
An estimated 40,000 people in the US are thought to be involved in "professional" dog fighting, using some 250,000 dogs.
These dog fighters train their pit bull terriers for maximum aggression before putting them in the ring to fight matches, publicised by underground networks.
Crowds watch and often place bets as the dogs, their jaws trained to grip ferociously hard, seek to tear each other apart for an hour or more.
As much as $100,000 (Ł50,000) can be staked on a fight between champion dogs, according to the Humane Society of the United States.
The dog that wins will live to fight again. But the loser is likely either to die from blood loss, shock and injury, or be killed by its owner as no longer profitable.
Meanwhile, tens of thousands more people - often gang members - take part in so-called street fighting, where dogs are pitted against each other in impromptu bouts in alleys or empty buildings.
It was in July last that Vick and three others were charged by a federal grand jury in Richmond, Virginia with conspiring to engage in competitive dog-fighting, procuring and training pit bulls for fighting and conducting the enterprise across state lines.
The court papers in Vick's case expose some of the brutality involved in a practice that seems to be concentrated in America's South and eastern states.
The footballer and his friends, all of whom have agreed plea deals, are accused of running an organised dog fighting operation called Bad Newz Kennels over several years.
When Vick's property in Virginia was raided, 54 pit bull terriers were found, some with apparent dog fighting injuries, as well as training equipment like a treadmill and a stick used to pry open dogs' jaws.
The men took their prize dogs across state lines to fight and wagered thousands of dollars on the outcome, the court documents say.
They also "executed" eight dogs that did not perform well in training, with hanging, drowning and electrocution among the methods used, prosecutors allege.
Although properly-raised pit bull terriers can make good pets, according to reputable Georgia breeder Tara Vickers, fighting dogs - having been trained to attack other animals - are impossible to re-house safely.
In the UK, the breeding, sale or exchange of pit bull terriers is banned under the Dangerous Dogs Act 1991 and people who already own pit bulls must keep them muzzled and on a lead in public.
No-one knows what motivated 27-year-old Vick, with his multi-million dollar American football contract, to venture into the murky world of dog fighting.
But there is evidence to suggest that its growth nationally is related to its adoption as a part of violent street culture.
Of course those convicted of dog fighting in the US face up to five years in prison and a possible $250,000 fine.
But the problem for the authorities is tracking down either the secretive organised networks or the individuals involved in street fights.
The entertainment some find in its brutality - and more importantly the money involved - make it irresistible to many people.
While the dogs keep winning, they can earn their owners thousands of dollars in gambling profits and by producing puppies with a "desirable" bloodline.
John Goodwin, an expert on animal fighting for the Humane Society, says one way to track the prevalence of dog fighting is to monitor the number of pit bulls coming into animal rescue shelters.
Whereas 15 years ago 2-3% of the dogs brought in were pit bulls, the breed now makes up 30% of the total nationally and 50% in some areas, he said. One shelter in Mississippi reported taking in 300 pit bulls, of which 60% had scars indicating they had fought.
"Urban areas are where a lot of the growth has been and the shelters get inundated with the castaways from dog fighting," Goodwin said. "Dog fighting has become popular in gang culture."
Of course, many pit bulls, particularly in the rural South, do not make it into shelters, Goodwin adds, because the owners simply kill them if they are no longer of use.
Life as a fighting dog is neither pleasant nor long, according to investigations by animal welfare groups such as People for the Ethical Treatment of Animals (PETA) and the Humane Society.
Pit bull puppies bred by an organised operation will be taunted to make them more vicious and kept chained and hungry.
They will be forced to run on treadmills with "bait" animals such as cats dangled in front of them - the reward usually being to maul them afterwards - and encouraged to hang by their jaws from chains to strengthen their bite.
Their strength built up, they then progress to "test" fights against older animals.
Only the young dogs that display sufficient aggression and "gameness" - the willingness to carry on fighting even when exhausted and bleeding - will be used in competitive matches. The others are usually culled.
The fights, staged in a small, square enclosed pit, can last an hour or more.
Some breeders cut off their dogs' ears so that rivals cannot bite onto them, file their teeth to make them sharper and pump them with steroids, said Dahpna Nachminovitch, of Peta.
Dr Randall Lockwood, a psychologist and senior vice president of the American Society for the Prevention of Cruelty to Animals, says there seems to have been a shift recently towards more brutal and vengeful treatment of the animals as dog fighting has been increasingly adopted by gang culture.
"Part of the psychology of dog fighting is the same as other forms of animal cruelty - a lot of it is about power and control," he said.
Add to this the dog fighter's identification with his animal in the ring - and desire to win "bragging rights" - and the scope for violence is great.
"The dog fighter sees his dog's victory as having a direct reflection on his strength and manliness, which I think is one of the reasons that we see brutal treatment of animals that don't perform well," Dr Lockwood said.