Basically, for many websites, as well as basically all software one installs, the sign-up or installation process requires you check a checkbox or click a button saying "I accept XXX terms and conditions"/"I accept the licensing terms".
I'm curious how this can be considered enforceable, considering that the person "agreeing" to the dialog can arbitrarily manipulate the contents of the agreement terms:
It's been my impression that the explicit agreement indicated by the checkbox or clicking of "agree" is the action that the enforcability of the terms of service hinge on .
Is this correct, and if so, how can contracts like this be considered enforcable? While it takes slightly more effort, the click-wrapper on most software can be manipulated in a similar manner.