Maybe a better example: Imagine your eazy-pass was mis-programmed. Going over the GG bridge, you get $$ credited to your account each trip rather than -$$ subtracted. So, depends on if the ez-pass was hacked by the user or just broken/mis-programmed by the EPA.
There's a graduated response to discovering that though, you could:
1) call up ez-pass and let them know
2) think "it's not my problem" and not let them know
3) decide to drive over the bridge more often
4) mention it to all your friends and suggest they drive over the bridge more often
5) strap your ez-pass transponder to a quadcopter and fly it in continual circles past the transponder reader.
I'm not sure where the line is, but somewhere between 3 and 5 is probably "fraudulent" behavior - at least according to my personal ethical standards (even #2 is clearly "wrong"), there's almost certainly a technical legal definition of "fraud" that applies somewhere along that line too.
