oh go on.. we might as well.... the HP connection can be slim, Jay and I tried this earlier and had gaps for several letters so be loose in your interpretation! loose is always good anyway 
Abracadabra
Black - Sirius the prisoner of Azkaban
Chamber of Secrets. Leaky Cauldron. Cruciatus Curse. Damn, and I promised myself not to get drawn into this ..... 
Dumbledore (Dead.)