Rape complainants are being told they must hand over their mobile phones to police or risk prosecutions against their attackers not going ahead.
Consent forms, which ask permission to access messages, photographs, emails and social media accounts, have been rolled out across the 43 forces in England and Wales.
The move is part of the response to the disclosure scandal, which rocked confidence in the criminal justice system when a string of rape and serious sexual assault cases collapsed after crucial evidence emerged at the last minute.
Police and prosecutors say the forms are an attempt to plug a gap in the law, which cannot force complainants or witnesses to disclose their phones, laptops, tablets and smart watches.
Liam Allan, who had charges dropped against him when new material surfaced, has said the new measures were “a step in the right direction”.
He told talkRADIO’s Julia Hartley-Brewer: “I can understand the concerns and I really sympathise with your life being stripped apart but I think there is so much focus on the bad things that could come of this.
“People are talking about it deterring complainants but I think it is the reaction that is going to deter them rather than the consent forms themselves.
“They have been painted as ‘a digital strip search’ but I think it is the right step as long as there are limitations.”
Director of Public Prosecutions Max Hill said digital devices will only be looked at when they form a "reasonable line of inquiry" and only "relevant" material will go before a court if it meets "hard and fast" rules.
"If there's material on a device, let's say a mobile phone, which forms a reasonable line of inquiry, but doesn't undermine the prosecution case and doesn't support any known defence case, then it won't be disclosed," he said.
But Northumbria Police and Crime Commissioner Dame Vera Baird said the forms are just part of the problem as police and prosecutors look to harvest third-party material, such as school records and medical notes.
"The police are really saying 'If you don't let us do this, the CPS won't prosecute'," she said.
"It is a real concern that people will be put off making a complaint in the first place if it's widely thought they are going to have to hand over lots of personal data - everyone lives on their phones, particularly teenagers."
In the lead-up to trials, police and prosecutors are required to hand over relevant material that can undermine the prosecution case or assist the defence.
The regime came under sharp focus from the end of 2017 after a string of defendants had charges of rape and serious sexual assault against them dropped when critical material emerged as they went on trial.