[VoiceOps] fraud protection

[Mark Kent]

Hello,

We just had an unfortunate compromise and racked up a large amount of
calls in a 12 hour period. The attack seems to be for financial gain
in that the most frequent destination is a conference call service in
Poland, that possibly keeps calls open waiting for a PIN to be entered.

Is there any basis for expecting that the upstream carrier should have
some protections that would limit our liability?

Thanks,
-mark

P.S.  For those people who feel compelled to point out that we should
have (better) protection on our end: Yes, Thank you, message received!