Caged criminals have complained that government officials are ordering internet firms to block access to videos of violence and drug-taking inside prison.
A group claimed that accounts on social media sites have been deleted and access to videos by users in the UK has been banned.
It published a screen shot that showed a notice from Instagram which advised that viewing of an account had been restricted in Britain due to a government request or court order.
The group publishes videos taken by prisoners on mobile phones, which are illegal in jails though possession of them is widespread.
It even operates a website featuring a shop selling a miniature “jail phone” of a type that has been hidden inside Mars bars and smuggled into jails by visitors.
It costs £41 and is thought to be of an all-plastic construction to evade security checks using metal detectors.
One recent video showed a huge quantity of drugs that is said to have been delivered into a prison in three packages by drones.
They were shown laid out on a table alongside a row of nine mobile phones whilst a man put small white cube on a digital weighing device.
“…that’s £100 right there,” said the prisoner, before putting a larger block on the scales.
An open shopping bag containing what looked like cannabis buds could be seen on the table, along with two large transparent plastic bags which also apparently contained the drug.
A pile of small “draws” of weighed-out drugs wrapped in pieces of the shopping bag could be seen to one side, along with a slab of something which could also have been an illicit substance.
Some 30 other oval-shaped packages could also be seen, which looked like they contained drugs that were tightly wrapped in cling film.
The location of the prison was not disclosed, though the unseen man featured in the video spoke with a London accent.
Others videos show parties in cells and prisoners being viciously assaulted over drugs debts or allegations of informing on fellow lags.
Many feature prisoners high and apparently in distress after overdosing on the illegal synthetic cannabis substitute known as Spice.
The consumption of Spice appears to be widespread in prisons and videos issued by the group are often accompanied by cautions warning against using it.
One video showed a man hung up by his ankles and apparently being punished.
His genitals were exposed and another prisoner was blasting water from a hose at him as he flapped around helplessly.
The expression on the man’s face suggested that he may have been high on Spice or otherwise mentally-disturbed.
Other prisoners, who had accents which suggested they were from the Liverpool area, kicked him and laughed.
Numerous videos showed prisoners apparently high after overdosing on Spice and hallucinating.
Other looked on and laughed and even beat those under the influence.
Some of the victims in the videos may have been deliberately given an overdose of the drug for general amusement or punishment.
One clip showed two men in a laundry area being given huge hits of Spice from “bongs” made from plastic water bottles.
They both soon slumped to the floor – one of them was kicked after he knocked over a box of washing powder whilst writhing around on the floor.
Another showed a prisoner said to be serving life for two murders brandishing what he claimed was a lock knife in his cell and giving shout-outs to friends and family.
The group also publishes videos made by criminals from across the world, including one featuring a man speaking German and English that claimed to show ten million euros in cash being counted after a cocaine deal.
Shot outside prison, the video showed bundles of 500 euro notes piled up on a table while the man used a machine to count bundles and check for fakes with a built-in ultra-violet light.