Police in the UK have the power to seize mobile devices from any traveler entering the country, and can retain their personal data for as long as they see fit, according to a report from the Telegraph. Such blanket powers are outlined under UK counterterrorism laws, and are broadly applied to thousands of travelers each year — regardless of whether police establish grounds for suspicion before confiscating a device. The revelations, published late Friday, have raised concerns among civil libertarians and privacy advocates, and an independent reviewer is expected to propose tighter checks on border police this week.

According to the Telegraph, UK border officials can download a person's photos, contact lists, and call logs, and retain them for "as long as necessary" — even if a traveler is allowed to proceed after being stopped. Authorities can also retain information on who a traveler texts or e-mails, though they remain barred from seizing the contents of these messages. Up to 60,000 travelers are "stopped and examined" every year under powers delegated by the Terrorism Act 2000, but the number of seized mobile devices remains unclear.

Considering the high volume of travel that the UK sees every year, the procedures could be applied to a broad range of international passengers. In 2012, an estimated 70 million people traveled through London's Heathrow Airport alone, according to the most recent data from Airports Council International.

"ordinary travelers need to know that their private information will not be taken without good reason."

Under the Terrorism Act 2000, police can detain and question a passenger for up to nine hours to determine whether he or she poses a security risk, and can do so without prior authorization or proof of suspicion. David Anderson, the UK's independent reviewer of counterterrorism laws, acknowledges that mobile phone data remains critical to police investigations, though he says there should be stronger provisions to guarantee that officers don't abuse their power. Anderson will present recommended changes to UK counterterrorism policies this week, in an annual report.

"Information downloaded from mobile phones seized at ports has been very useful in disrupting terrorists and bringing them to justice," Anderson told the Telegraph. "But ordinary travelers need to know that their private information will not be taken without good reason, or retained by the police for any longer than is necessary."

London's Metropolitan Police Service insists that data seizures are only conducted under appropriate circumstances.

"As with any power to detain an individual, [Terrorism Act 2000] is used appropriately and proportionally and is always subject to scrutiny by an independent reviewer of UK anti-terror laws," a Scotland Yard spokesperson said in a statement to the Telegraph. "Holding and properly using intelligence gained from such stops is a key part of fighting crime, pursuing offenders and protecting the public."