I don't see why it couldn't be built, and actually I refer back to 10 years, 15 years, or 20 years ago. The technologies of those days were emerging technologies, and the proper guidelines were put in place to make sure there was not abuse. Law enforcement was, and still is, and under the present circumstances would be required to obtain judicial authorization in order to do the intercepts.
On March 25th, 2009. See this statement in context.