Victims of crime, including those relating to rape, should be asked to hand over their phones to the police or to law enforcement not to risk going ahead.
Consent forms have been introduced in England and Wales requesting permission to access information such as emails, messages, and photos.
There were a number of rapes and serious cases of sexual assault after key evidence emerged.
Victim Support said the move could prevent the victims from moving forward.
- Director of the Prosecutor's Office criticized for failure of cases
- Hundreds of cases dropped for disclosure failure
But police and prosecutors say the forms are an attempt to close a loophole that states that complainants and witnesses are not can be forced to disclose cell phones, laptops, tablets or smart watches.
Procurator Max Hill's director said they would only be investigated where they form a "reasonable line of investigation." Only relevant material is brought to court if it meets strict rules.
Digital consent forms can be used by complainants in criminal investigations, but are most commonly used in rape and sexual assault where complainants often know the suspect.
The forms state that victims are being given the opportunity to explain why they do not want to give their consent to the police, but they are also informed: "If you deny the police permission to investigate or the prosecution reveals material, that the defendant's fairness then it can not be possible for the investigation or prosecution to continue. "
By Clive Coleman, Legal Correspondent to the BBC
The Survey of Victims, Complainants and witnesses ̵
Most modern phones have more computing power than the first NASA missions.
They include photos (sometimes intimate), emails, and social media posts (sometimes very personal, sometimes indiscreet), not to mention hurried text messages.
Many people jealously guard the contents of their smartphones and consider a police investigation a violation of privacy.
Civil Liberties groups have expressed concerns that victims could not report offenses if they fear their smartphone will be investigated.
However, police do not have the authority to simply take the phones of victims and witnesses, so consent is the only option. Will people volunteer their devices? Would you?
The issue of disclosure came to the fore when several lawsuits were dropped because evidence was not shared with defense lawyers.
There was concern that evidence was not revealed soon enough.
One of the defendants concerned was then-22-year-old student Liam Allan, who dropped the charges when critical material emerged during his trial.
The Metropolitan Police apologized to Mr. Allan for a series of errors in the case, in which he was unjustly charged with rape.
It is understood that there were messages found on the alleged victim's mobile phone that said what a kind person Mr. Allan was and how much she loved him. There was also evidence of rape fantasies, confirmed Mr. Allan's lawyer Simone Meerabux at that time.
Mr. Allan later told the BBC that the matter had "torn apart my normal personal life."
The CPS then launched a review of all rapes and charges of serious sexual assault in England and Wales and has implemented an improvement plan with the police to try to fix bugs in the system.
But Rachel Almeida of Victim Support said it was "very likely" that the police got the opportunity access to the personal information on their phone access would be in the plight of the victims.
She said, "We know that rape and sexual assault are already under-reported, and unfortunately, these victims could continue to prevent victims from gaining access to the judiciary they deserve."
A legal challenge is already underway, said the Center for Women's Justice. It is expected that at least two women will file a lawsuit that has been told their cases might collapse if they do not cooperate with requests for personal information.
The Center for Women's Justice expressed "serious concern" about the police's "excessive disclosure requirements".
"Most complainants fully understand why the disclosure of communications to the defendant is fair and reasonable, but it is unclear why their past (including sexual history) should be available for selection."
I go back to the bad old days when victims of rape are treated as suspects, "said Harriet Wistrich, director of the organization.
The CWJ also warned against a" deterrent to rape allegations "example a woman called Olivia, who recently reported rape to the police.
Olivia said, "My phone documents many of the most personal moments in my life and the idea that strangers comb it to use it. I feel against myself, as if I had been hurt again.
Civil Liberties Charity Big Brother Watch said victims do not have to "choose between privacy and justice."  "The CPS insists on digital stripe searches of victims who are unnecessary and their rights "The organization added."
Rachel Krys, co-director of the Coalition Against Violence Against Women, said: "We have an extremely serious problem with the persecution of rape in this country and that is a fact that most Rapists get away.
"One reason for this is that the investigations too often focus on the character, honesty and sexual history of women, though by rules designed to prevent this rather than the actions and behavior of the defendants."
There is no reason for rape investigations to routinely demand such a violation of women's privacy.
Scotland Yard said it recognized the "uncomfortable" and "inconvenient" nature of handing over equipment to the police.
"People who have been victimized and subjected to serious sexual assault, for example, is one terrible thing that should happen to them, and you do not want to make it worse by making your life really hard.
"But to Persecute the Offender, the Way The law is constructed so that we have these obligations, so we must find a way to obtain this information with a) as much consent as possible, which is informative and b) with a minimum of interruptions and irritations and fixes for the person whose phone it is that we are dealing with. "