[saryant]

Yes, you agree for both the fare rules of the specific ticket you bought and the airline's contract of carriage, both of which are approved by the Department of Transportation. And (at least) the CoC prohibits hidden-city ticketing.

[jamesaguilar]

Thanks! I could not find the contract on JetBlue's site when I went looking last night. But here is the contract for American Airlines.

http://www.aa.com/i18n/customerService/customerCommitment/co...

As you can see, hidden city routing is prohibited, and they retain the right to assess the difference between the ticket you actually used and what you paid if you engage in the practice.