If you're asking whether I'd exploit it, the answer is a firm no. I'm not the biggest fan of the MTA (nobody who lives in NYC for any substantial amount of time is), but the personal benefit would be minuscule compared to the consequences.

More to the point, making a public display of weaknesses in the MetroCard might finally get the MTA off their ass and onto that modernization project they've been promising for the last 15 years ;)