Dangerous checks, no balances

I always knew that those checks sent by the credit card companies were dangerous.  You pay a cash advance fee, and interest; it’s extremely unlikely that you couldn’t get better rates elsewhere if you urgently need cash.  Now I have received from Discover Card some unilateral revisions to the Cardmember “Agreement:”

We will charge you a Returned Discover Card Check Fee each time we decline to honor a Discover Card cash advance check, balance transfer check, promotional purchase check, or other promotional check.  The amount of this fee is $25, except [if we have already done this to you within the past six months] it will be $35.

So, any time they want, if I try to use one of those checks, they can pick up an easy $25 or more.  Probably put something nasty on my credit report, too.