The ACLU has filed two lawsuits since the Michael Brown shooting in Ferguson:

On 2014-08-15, Hussein, St. Louis County, Missouri Highway Patrol, and City of Ferguson signed an agreement stating that: "Parties acknowledge and agree that the media and members of the public have a right to record public events without abridgement unless it obstructs the activity or threatens the safety of others, or physically interferes with the ability of law enforcement officers to perform their duties." Here's the PDF of the agreement.

However, reporters were arrested on 8/18 as the media blackout continued.

 

Here's an article about the lawsuits.

The ACLU of Missouri, a state chapter, has also brought in legal observers from the National Lawyers Guild wearing neon green hats to observe the protests. Amnesty International also has observers on the ground. One National Lawyers Guild observer was arrested on the night of August 19, 2014.

(source)