> By the way: If the FBI is so successful using traditional police tactics to infiltrate "cybercrime syndicates," why do they need a "front door" to our devices?
Just like the old-fashioned police work they did here which you mentioned, the FBI in the past has been able to use warrants to obtain unilateral access to safe deposit boxes, drill open personal safes stored at home, search through a person's desks, closets, bedrooms, etc. for particular items, and more.
That is the level of access FBI Director Comey is saying that they need (the ability to enforce warrants for the same types of searches required for "papers and effects") for the same reasons that the FBI has needed such access for investigations in the past.
He isn't asking for the ability to conduct passive or mass surveillance, or even the ability for FBI to unilaterally enforce a warrant. He's asking for the ability of the device manufacturer themselves to be able to comply with a warrant if one is offered up. The cryptographic technology necessary to do so already exists, in a way that would limit access to the manufacturer, so that's not the issue.