The cops don't need special access to kick your door down, and if they do, then you know that someone (not necessarily a police officer) broke in. To me, a front door approach means no access not available to private citizens without a warrant based on probable cause (with the usual exceptions); in other words, no special access; especially if surreptitious. If the police want to tap someone's phone, then they should have procure a warrant, serve it on the provider, and then install, maintain, and operate the equipment themselves (at taxpayer expense) without any further need for cooperation from the provider. And once the court ordered data have been procured and no more orders are likely to be forthcoming, the equipment should be removed. And I actually am comfortable with the recipient of a search warrant being required to cooperate fully with the search, even to the extent of providing the keys needed to decrypt sought after data as again, he knows he's being searched and he can change the keys when the cops leave (but I'm not comfortable with luggage locks the TSA knows how to pick; I'd rather not lock my luggage at all, if that's the only other choice). It also means that it should be *illegal* for custodians of the data and property of others to voluntarily surrender them to government officials without a warrant, unless it would be legal to grant such access to private citizens (and there should be no limits on liability in such cases). But while special access approaches may sometimes be necessary, they should be rare, and avoided if at all possible; and should only be accessible by court order.
The assumption should be that if the police can do something, others will be able to, legally or not; and that there will always be some police officers and other government officials and agents who will abuse their authority, even if the vast majority of their peers are paragons of virtue. The purpose of the Fourth Amendment is not to prevent a totalitarian state (such states feel free to ignore legal requirements whenever they find them inconvenient) and it's not to protect "criminals"; rather, the purpose is to prevent abuse of authority; and to protect people from intrusion and/or harassment when there is no logical reason to believe they have broken the law.