I read a post on Bersa Talk yesterday about a man in Atlanta who was car-jacked by an armed assailant and used a taser to defend himself. The infuriated car-jacker then shot the driver five times.
People, if you don't want to be a victim and choose to arm yourself, arm yourself with a weapon capable of ending an attack, not just making the bad guy really angry.
Police departments don't usually tase aggressive suspects who are armed with a firearm. If he points the gun at an officer or another person, they shoot the suspect, and they don't try to wound or disable, they shoot to neutralize and end the threat. That almost always means they aim for the center of mass, and the suspect is usually seriously wounded or dies from his injuries. Police officers are under no obligation to let armed suspects fire first before returning fire.
Tasers are generally used on agressive suspects who pose a threat but aren't armed with a firearm. Generally there are more than one officer present, and as soon as the suspect falls down after being tased, he is rushed and subdued by multiple officers.
As one commenter at Bersa Talk said, this poor crime victim brought a taser to a gun fight. And he lost.