Is it moral to knowingly ignore or violate a website's terms of service?

Suppose that during the sign up process for a website you are presented with some terms of service and a checkbox indicating that you have read them, and that the checkbox is disabled until you've scrolled to the bottom of the terms. Leaving aside the question of whether the terms should be enforceable in a court of law, is it moral to simply scroll to the bottom and click the checkbox without reading, or to later do something that you know was expressly prohibited by the terms? If so, what kind of obligations do you have when the terms aren't presented so unambiguously (e.g. there's just a link in the site footer that says "terms of service") or are filled with complicated legalese? If not, is there (or should there be) any way for a site owner to communicate the terms of using the site, or does putting an HTTP server on the public network thereby permit anyone in as long as there are no technical barriers put in place?