Rowling said somewhere in an interview that there were ways of making yourself impossible for an owl to find; whether this is a blanket affect or could be lifted for select targets is unclear. Otherwise, the Aurors could have just owled the Death Eaters something and then followed the owl to their hiding spaces.
Rowling said somewhere in an interview that there were ways of making yourself impossible for an owl to find; whether this is a blanket affect or could be lifted for select targets is unclear. Otherwise, the Aurors could have just owled the Death Eaters something and then followed the owl to their hiding spaces.