A security researcher got an eyeful of a sex worker's client base when he investigated a VoIP service whose "burner" phone numbers are being recycled.

Neohapsis Labs Senior Security Consultant Rob Beck was on an engagement that had him checking out the "burner" feature of a VOIP company.

It turns out the disposable numbers aren't being disposed of -- they're being given to the next customer in line.

Beck found out quickly and explicitly that the service had issued him the "disposable" number of an escort -- and her clients clearly thought she was still at the same number. Beck said: "Going based solely on the contents of the SMS messages received, as well as some of the voicemails left on my trial number messaging service, the previous owner was also a specialized professional who is use to charging an hourly rate; lets just say that her chosen profession was of a much more discreet and intimate nature."

It turns out the disposable numbers aren't being disposed of -- they're being given to the next customer in line.