We have no way of knowing how many Fraud cases there are with the Uber Fuel Card. 
We do know that Uber is no help whatsoever if you discover a case of Fraud with your Fuel Card.
A normal credit card will limit your liability in the event of fraud, not Uber.
The best thing to do if you suspect Fraud or lose your Uber Fuel Card is to IMMEDIATELY

_______________
UBER Website: FOR PARTNERS, ACCOUNTS AND PAYMENTS
I lost or misplaced my Fuel Card
If your card has been lost or stolen, visit your fuel card page below or sign in using your app. Select REPLACE LOST CARD and complete the shipping info. We'll cancel your old card and send you a replacement.
You can also call (844) 271-5657 to cancel your card.
We do know that Uber is no help whatsoever if you discover a case of Fraud with your Fuel Card.
A normal credit card will limit your liability in the event of fraud, not Uber.
The best thing to do if you suspect Fraud or lose your Uber Fuel Card is to IMMEDIATELY
- Report in-App, Account > Help > Account and Payment > Fuel Cards (scroll to bottom) > I lost or misplaced my Fuel Card
- or Report it online.
- or call (844) 271-5657 for (Comdata who issued the card) to cancel your card. Comdata cannot process a fraud notification or refund request.
_______________
UBER Website: FOR PARTNERS, ACCOUNTS AND PAYMENTS
I lost or misplaced my Fuel Card
If your card has been lost or stolen, visit your fuel card page below or sign in using your app. Select REPLACE LOST CARD and complete the shipping info. We'll cancel your old card and send you a replacement.
You can also call (844) 271-5657 to cancel your card.