The kiosks have enabled people to recycle more than a million electronic devices so far. They've also installed sophisticated security systems but some police agencies say it's not enough.
The ecoATMs are unattended kiosks in shopping malls where people can recycle cellphones and other electronics for instant cash. For instance, an iPhone 5 in perfect condition can get you $274.
The company has installed security systems to prevent cell phones thieves from cashing in. Customers have to swipe a picture ID and cameras take your photograph. A thumb print is also required.
The transactions are monitored remotely from the firm's San Diego offices.
"If there's a problem with that ID or if the people don't match, that transaction's declined," said ecoATMs' Ryan Kuder.
But with the epidemic of smart phone thefts, some police agencies are worried that these kiosks are becoming repositories for the thieves. They say many thieves can circumvent the security measures, allowing them to get rid of the phones quickly before the victim can file a police report.
San Francisco police say they're generally satisfied with the security at the kiosks in two malls in the city.
The kiosk at the San Francisco Shopping Center has received around 5,000 electronic items. Only three were found to be stolen. But there may have been many more stolen phones in certain kiosks that were not reported by the victims.
"That's correct. There's, you know, really, if you sell us your phone and it doesn't get reported stolen, it's kind of difficult to determine whether it's been stolen or not," said Kuder.
Last year, Tanforan Shopping Center said no to a kiosk because the company couldn't get a business permit.
San Bruno police say they concluded that the kiosks violated the state business and professions code because there was no attendant who could verify that the items were not stolen.
"If you put your thumb print on the screen but you're not in any type of law enforcement databases, then yes you have a thumb print but it's difficult to match up to who that person may be," said Sgt. Michael Barton of the Daly City Police Department.
Law enforcement officials say having an attendant at these kiosks is the best deterrent to illegal activity.
Kuder says they're constantly working with law enforcement to improve the kiosk's security.