As I understand it, the allegation here is that only by following the internal policies would their activities be allowed under the Fourth Amendment, and by bre

As I understand it, the allegation here is that only by following the internal policies would their activities be allowed under the Fourth Amendment, and by breaching these policies their actions are illegal under the Fourth Amendment, not under any more specific law. Of course, as you say, this all depends on the nature of how the internal policies were breached, so it's far from a given.