Forbes:

The U.S. federal government, from the FBI to Immigration and Customs Enforcement, has been handing millions to Cellebrite to break into Apple and Google smartphones. Mr. Balaj (Forbes agreed not to publish his first name at his request) and others on eBay are now acquiring and trading Cellebrite systems for between $100 and $1,000 a unit. Comparable, brand-new Cellebrite tools start at $6,000.

More importantly:

Rather than return the UFEDs to Cellebrite so they can be properly decommissioned, it appears police or other individuals who’ve acquired the machines are flogging them and failing to properly wipe them. Cybersecurity researchers are now warning that valuable case data and powerful police hacking tools could have leaked as a result.

This was one of the scenarios that emerged, back in late 2015, during the Congressional hearings that followed the San Bernardino shooting, asking Apple to build a golden key to allow law enforcement to unlock any iPhone on-demand. The concern then was that the golden key might get into the wrong hands, risking the data and privacy of the larger iPhone community.