Three times. Once because some guy in an apartment above me decided to beat the ^QE#$%$# out of his gf. Cops came and arrested him. Another time I saw an accident and called to get the EMT's on the scene. Last was by accident.... kinda funny. I got a new cell phone my father bought me in Germany. I was playing with the thing and it had something that said "notruf" ... it didn't occur to me to look it up, I just figured I'd click the button to see what it did, I figured with no sim card in the thing yet it wouldn't do anything anyway. Oops. Notruf of course is German for "emergency call" so the thing dialed 911. I tried to explain to the operator that I called by mistake, but he thought I was being kidnapped or something and kept saying things like "if there is someone within earshot threatening you or if you are in danger, just say "no, everything is fine tonight" etc.