Hong Kong's High Court ruled on that warrantless searches of arrestees' cell phones could go ahead, as long as a full account of the search was made.



The decision overturned an ruling in a case involving pro-democracy activists, which said police could only scan arrestees' phones in "exigent circumstances," meaning emergencies involving an imminent threat to the public or to police officers.



But three High Court judges found on that no warrant should be required to search cell phones in any other situation, if obtaining a warrant wasn't "reasonably practicable."



Instead, officers only needed to show that they had "a reasonable basis for having to conduct the search immediately," which could include the need to investigate a suspect or to preserve evidence that could be of use elsewhere.



Police first started scanning data on people's cell phones in Hong Kong during the 2014 pro-democracy movement, after seizing them from five protesters arrested during a rally.



The first case involving phone data came to court after the five challenged the admissibility of phone data obtained without a warrant.



's judgment stated that, although the power would interfere with the arrested person in Article 30 of the Basic Law and Article 14 of the Hong Kong Bill of Rights Ordinance, the power to authorize the police was still "proportional."



It also ruled that refusing to hand over your phone password didn't constitute obstruction of police in the course of their duties.



Vague ruling gives police wide leeway

Civic Party lawmaker Alvin Yeung said the ruling was vague enough to give police huge scope to interpret exactly in what circumstances it would be permissible to scan someone's phone.



"There have been a number of cases [involving phone data] in the past 10 months," Yeung said. "Some young people wearing black [the color of the protest movement] have been stopped on the streets by police, who threatened them with charges of obstructing a police officer if they didn't switch on their phones."



"Even if the police have the power to do this, will they use it in a reasonable manner?"



"There are plenty of real-life examples proving that the police don't respect the rules, or are abusing their power," he said. "The court has now handed the power to decide what constitutes reasonable circumstances to the police, which makes the situation far worse than it was."



Alan Wong of the Progressive Lawyers' Group agreed, saying the vagueness around the concept of a "reasonable" justification was worrying.



"I think the biggest concern is that the police will go through someone's phone if it's not locked," Wong said. "What exactly constitutes a reasonable basis? It's very vague, and open to debate."



"Such a thing can be very subjective," he said.



Police are bringing more than 600 protest-related prosecutions dating from the anti-extradition and pro-democracy protests that began in on a range of charges including "unlawful assembly, assault, arson and rioting.



More than 7,700 people have been arrested since the movement began.



In , the U.S. State Department issued an annual report that cited political arrests of Hong Kong activists as part of a bid to discourage protesters and keep numbers down, as well as "multiple sources" saying that Chinese state security agents were monitoring political activists and academics critical of the ruling Chinese Communist Party.



The report found that the authorities, whether in Hong Kong or Beijing, had "restricted or sought to restrict the right to express or report on dissenting political views, particularly support for Hong Kong independence."



It said the prosecutions of activists and refusals to grant approval for some assemblies had infringed on the rights of Hongkongers to peaceful assembly and protest.



Rights groups have also hit out at the Hong Kong police for using excessive force to disperse crowds or arrest individuals suspected of participating in violent protests on several occasions.



The U.N. Human Rights Office has said there is “credible evidence” the Hong Kong police had “employ[ed] less lethal weapons in ways that are prohibited by international norms and standards” when conducting crowd dispersal operations.



Reported by Lau Siu-fung for RFA's Cantonese Service. Translated and edited by Luisetta Mudie.