I believe Jim has said or at least implied that trying to use Harry's name against him can backfire to the person or entity who does so. Also, along time ago Jim said there will be a time when Harry will be summoned (by name) the same way Harry has called upon Lea, Mab and others. That won't end well for whoever does that. There is also something Harry says at the end of Storm Front, "My name is Harry Blackstone Copperfield Dresden. Conjure by it at your own risk..." Even if Jim hadn't full planned out what the risk of using Harry's name against him would be when he wrote that first book, he obviously had something in mind. In fact I believe there is a WoJ to that effect.
So aside from Harry using his will as a mental weapon against the Outsiders and immortals in general, and his ability to name things and alter their essential character, Harry's name is a weapon and or booby trap from anyone who thinks they can use Harry's true name against him.
