I added that in an edit, but basically, it doesn't grant any powers by itself. It simply aids the court in carrying out its jurisdiction. So, when it comes to

I added that in an edit, but basically, it doesn't grant any powers by itself. It simply aids the court in carrying out its jurisdiction. So, when it comes to wiretapping, there are specific statutes that authorize wiretapping in such-and-such circumstances. The court can then issue writs as needed to carry that out, provided the writs meet fairly narrow criteria (not overly burdensome, only targeted at an entity "close to" the case at hand, only targeted at an entity whose actions are "necessary" and where there's no other way to carry out the jurisdiction, rather than, say, just convenient) and the writ must have some kind of antecedent in common law, which is a somewhat fuzzy topic, but it boils down to "the writ can't just be pulled out of thin air, there's a set of traditional writs and it should appear to be consistent with that set".