Wise? Hell no.
If six armed thugs take you by surprise and demand your wallet, trying to get the drop on them and gun them down would be perfectly justifiable. It would also be rather stupid.
And with cops, there's a lot more than six of them.
However, seeing things like the UCLA tazing makes me want to scream at the bystanders to attack the thugs, lock them up with their own handcuffs, and give them a taste of their own medicine.