Police are out of control; the militarization that has gone on since the beginning of the drug war, the complete lack of accountability and their blatant and sometimes open hatred and disregard for the civil liberties of the citizens they claim to protect to name a few. Those who think that this doesn't exist are the same who said "If you're not doing anything bad then you have nothing to be afraid of" when the PATRIOT Act was passed. Whether you're in the camp of Robert Higgs who believes there is no such thing as a good cop or the camp of Radley Balko who believes that there are good cops, the overall issue is that domestic policing in the US is a problem that needs to be fixed.
I'm a open supporter of police accountability sites such as Copblock and Photography is Not a Crime. These are two of the best sites out there when it comes to exposing police misconduct no matter who the victim of said misconduct is. In addition they both highlight police officers who cross the thin blue line who get punished by the same corrupt system that they are exposing. Obviously like any group they have their own share of criticism from both those within the movement and it's enemies.
One group within the police accountability movement that I believe is hurting the movement and giving more talking points to government defenders (collectively known as Blue Lives Matter or like some Anarcho-Capitalists say Blue Lives Murder) is the Black Lives Matter movement. The movement that spawned after the death of Michael Brown and trial of Darren Wilson in Ferguson, Missouri. When it started on it's face it had a legitimize set of grievances that appealed to the police accountability movement. However this is before the riots in Ferguson and Baltimore and most recently the movement assault on libertarian activist Adam Kokesh. Assault on innocent businesses and innocent people is wrong as is also collective judgement and punishment. Nobody has the right to assault another outside of self defense despite what some on the left and right think it's wrong. More evidence seems to emerge every so often that Black Lives Matter has devolved like most liberal movements into just being against anyone who isn't liberal and unfortunately a racial competent is involved too.
Not only do assaults on innocent people hurt the police accountability movement, their gun control stances hurt it too. Despite US Supreme Court rulings that haven shown that police forces do not have an obligation to protect individuals just enforce laws, government defenders continue to use the argument that any reforms such as actual accountability will prevent the police from protecting you. One of the solutions that should be included in any police reform proposal should be unrestricted civilian access to firearms. To quote Freedoms Phoenix owner Earnest Handcock "The second amendment is for everyone" Gun control laws only hurt innocent people and embolden those who want to commit acts of violence against peaceful people. As the old saying goes; "An armed society is a peaceful one".
With these acts I personally see no reason why any libertarian anarcho-capitalist could in good principal support the Black Lives Matter movement as a whole nor it's faces of the movement such as Cassandra Fairbanks (who many libertarians rightly and openly dislike). Support for the Black Lives Matter movement only give police statists more ammo to use against us which will undo much of the work the police accountability movement has done.