The latest roll out just occurred, known Panda 4.0. Essentially, the purpose is to penalize pages that have poor quality content.
These algorithm changes are often view in a negative light- "Oh no, will this hurt my ranking?" But it is critical to remember that the opposite can also be true: these changes can result in a big boost if you've done good legal content writing work in the past.
In short: if you use your legal website and blog to actually provide helpful, interesting, useful information to the public, then you never really have to worry about these updates.