It is tough and I'm not exactly sure where I stand on the actions by Anonymous yet.
Determining both the level of existing corruption and what is necessary to justify circumventing the rule of law are difficult grey areas. Several factors lead me to believe the police force does in fact have corruption issues. For one it is 96% white in a 70% black community. That stat implies (but does not prove) racist/corrupt hiring practices. Secondly, by replacing tear gas assaults with respectful dialogue the Missouri State Troopers, who replaced the Ferguson cops, were able to end the violence from protesters almost instantly. Finally, the fact that Ferguson police charged a black man for destruction of property because he bled on their uniforms while they beat him (posted by Cybercoma here) shows a deep level of corruption and potential racism.
So I guess the question is, does this level of corruption justify the cyber attacks and potentially endangering the lives of government and police members? Specifically, outing the addresses and identities of the mayor, cops and their families bothers me, because the angry mob could easily have attacked and/or killed innocent people in a fit of vengeance. The fact that those who are supposed to serve and protect the citizens of Ferguson clearly harm innocent people doesn't make the reverse acceptable. Shutting down phone systems and databases during such a frantic time could have also exacerbated problems. I would have rather Anonymous used their unique talents to help force change after the initial crisis was averted. I think using cyber attacks and the threat or actual release of sensitive information to force the replacement of police and government officials along with the creation of new laws would have been preferable.