The Easiest T&Cs to Accept

So I signed up for a trial of Adobe’s eSignature service Echosign today and was initially presented with the following screen asking me to accept their terms and conditions. I assume that the huge white space is where they were supposed to have been displayed. So I went right on and accepted.

The question now is where do I stand legally as I accepted a blank set of T&Cs can I be bound by the ones Adobe failed to display?