Many websites offer contracts to their visitors by "browse-wrap" (making an offer by notice, where not not using the site signals acceptance) or click-wrap (making an offer where clicking "I agree" or a similar provided UI element signals acceptance).
But a web site operator is not 100% in control of what the user actually sees. Users often have ad blockers, and it is common for those to now also block cookie consent notices. It would be technically feasible and possibly legally desirable to have some kind of "contract block" browser extension that explicitly tries to prevent the user from doing anything that would constitute agreeing to a contract.
For a browse-wrap contract, if the visitor did not have actual notice of the existence of the terms because their device categorically refuses to accept such notice, is the contract still formed? Would the web site need to be notified that the browser has refused to forward the notice to the user in order for it to legally count as not delivered? Or is this approach just dodging service/willful blindness on the information superhighway? Or does it depend on whether the user is deliberately making their device do this, versus whether this is a feature that the user is unaware of?
For a click-wrap agreement, if the user never actually takes the action that is specified to form the contract, is the contract still formed? Imagine if the user's browser has been programmed to replace all the "I agree" buttons with legally distinct "I reject" buttons that fire the same events. The offered contract says it can be accepted by doing a particular thing, but that particular thing is not done. Is the contract formed or not? Would the user's system somehow have to advertise that it is incapable of displaying "I agree" buttons, in order for that highly unusual configuration to be legally recognized?