A lawyer has dramatically withdrawn from pursuing alleged illegal file-sharers in the middle of a court case he brought.
The patent court in London is currently scrutinising 26 cases brought by ACS: Law on behalf of its client MediaCAT.
The law firm had sent thousands of letters to alleged file-sharers.
Those who received such letters may pursue ACS: Law for harassment, said law firm Ralli, which represents some of the defendants.
In a statement read to the court, solicitor Andrew Crossley said he had now ceased all such work.
He cited criminal attacks and bomb threats as reasons.
"I have ceased my work... I have been subject to criminal attack. My e-mails have been hacked. I have had death threats and bomb threats," he said in the statement, read to the court by MediaCAT's barrister Tim Ludbrook.
"It has caused immense hassle to me and my family," he added.
In September, ACS: Law was the victim of a cyber attack and it accidentally exposed thousands of its e-mails online when its website went live again.
These e-mails detailed all the people it was pursuing and the pornographic films they were accused of downloading for free.
The data breach is the subject of an ongoing investigation by the Information Commissioner, and Mr Crossley could face a hefty fine.
ACS: Law hit the headlines when it began sending thousands of letters to alleged file-sharers, on behalf of client MediaCAT.
Consumer group Which? has accused it of sending letters to innocent people, while some ISPs have refused to hand over details about their customers.
"It can be incredibly upsetting for people to receive these letters and they may well have a claim in harassment," said Michael Forrester, a solicitor at law firm Ralli, which represents some of the defendants in the current case.
Groups such as the BPI, which represents music labels, have criticised its methods.
Those methods hinge on a partnership between ACS: Law and MediaCAT, which in turn has signed deals with various copyright holders allowing it to pursue copyright infringement cases on their behalf.
The court heard that copyright owners receive a 30% share of any recouped revenue while ACS: Law takes a 65% share.
Members of the public who received letters were given the choice of paying a fine of around £500 or going to court.
Detractors have accused Mr Crossley of seeking to make money with no intention of taking any cases to court.
In his statement, Mr Crossley denied this.
"It has always been my intention to litigate and, but for the fact that I have ceased this work, my intention was to litigate forcefully in these 26 cases," he said.
Mr Crossley is subject to an ongoing investigation by the Solicitors Regulation Authority.
Even before Mr Crossley's statement, the court case had been highly unusual.
ACS: Law's client MediaCAT wants to drop the cases, and letters have already been sent to the defendants informing them that action against them has been dropped.
But Judge Birss said granting permission to discontinue the cases was not a simple matter, due largely to the fact that the actual copyright holders were not in court.
This meant that, in theory, these copyright holders could continue to pursue cases against the 26 defendants.
"Why should they be vexed a second time?" he asked.
Judge Birss also questioned why MediaCAT wanted to drop the cases.
"I want to tell you that I am not happy. I am getting the impression with every twist and turn since I started looking at these cases that there is a desire to avoid any judicial scrutiny," he said.
The case was made more complicated by the fact that a new firm, GCB Ltd, had begun sending similar letters, including one to one of the defendants who had been told just the day before that no further action would be taken.
Judge Birss said he was considering banning MediaCAT from sending any more such letters until the issues raised by the cases had been resolved.
Doing so, he said, would be a highly unusual move but one made more likely by the fact that Mr Crossley had said in his statement that there were "no new letters pending" and that GCB Ltd had also halted its work.
The judge was keen to find out what the relationship was between GCB and ACS: Law, something Mr Crossley sought to clarify in his statement.
He said that he had no connection with GCB Ltd beyond the fact that the founders of the firm had previously been employed at ACS: Law.
The case has raised some serious questions about how copyright firms pursue file-sharers.
Barristers acting on behalf of the accused questioned whether an IP address - a number assigned to every device connecting to the internet - could be used to identify the person who downloaded illegal content.
Barrister Guy Tritton also questioned the nature of the letters sent by ACS: Law, asking why it described MediaCAT as a "copyright protection society" - a title that he said was "misleading".
Judge Birss is expected to deliver his judgement on the case later in the week.