Here's a perfect example of police using tazers appropriately. The man caught on fire, but it doesn't matter because in this case police were completely justified in using the tazer. The guy had already slashed himself with a knife and was an obvious risk to their safety.
[i]And shepherds we shall be, for thee my Lord for thee, Power hath descended forth from thy hand, that our feet may swiftly carry out thy command, we shall flow a river forth to thee, and teeming with souls shall it ever be. In nomine patris, et fili, et spiritus sancti.[/i]