You missed the point of my last question. Right now. Today. You have an expectation of privacy in your own home. For anyone that understands how surveillance works, you would know that closing your door is pointless as far as keeping the sound in. By your logic, this is not appropriate. Because, "hey, you should know that it is easy to hear inside your home."

However, if police wish to violate this, using relatively common and accessible tools, they have to have a warrant. Consider the phone calls you place. These are just as exposed to third parties as any email you send. Yet to intercept them police need a warrant. For others to do so is illegal.

Note, the deciding point here is not that it is hard or easy to intercept your communications. Or sit outside with a microphone. The point is that those activities require a warrant. Because they are illegal otherwise.