A mobile phone stolen from the Foo Fighters concert at the Stadium of Light on Monday was traced within hours by police.
Detectives used a tracker app installed on the iPhone to track it down.
Late on Monday night, police received a report that an iPhone and purse had been stolen from a concert-goer.
They used using GPS tracking technology to locate the stolen items at an address in Whitley Bay, where they seized a further 30 mobile phones.
Detective Inspector Dave Swinburn said: “We urge everyone to protect their property from thieves.
“We always advise concert-goers to be extra vigilant due to opportunistic thieves and encourage everyone to protect their property and make the most of GPS tracking systems.
“A simple step like downloading an app can make the difference between losing the item forever or having it tracked, located and seized by police.
“For those who don’t have such technology installed on their devices, I’d recommend they register their goods with Immobilise, the national property register.
“By working together and following crime prevention advice, we can stop thieves in their tracks.”