There is no quick one click block button, but there is a block feature on the board and I strongly encourage you to use it.
Here's how:
Click on your profile.
Account > Account Settings > Ignored Users
Under "Add new user to ignore list" type name of user you wish to ignore.
You can then choose to ignore any of the following from that poster:
Posts, Messages, Mentions.
I routinely select all three.
Click add user and boom, now you will no longer see posts from Joe Ferguson forever (Quack, MD)
Unfortunately the ignore function isn't air tight. If another poster not already on your ignore list decides to quote Quack, MD then you will see his quoted content.
Welcome to the ignore feature, I encourage using it liberally. I think you'll find that it will significantly improve your PPP experience.
Cheers.