I don't agree with any of the comments that state a tether out on the field can not be messed with in any way and its malicious to do so. If a robot has a goal and is trying to score we are allowed to shove, pull, grab to prevent the scoring. A tether in my mind is no different, it is an extension of the robot used for scoring and I feel we are justified to attempt to stop a tether from scoring in the same manner as applies to robots pushing,pulling, grabbing, I guess doing donuts on it is a little extreme but you could say you were a bad driver.
I would hope that the refs see it this way also and don't give any special rulings to some of the crazy tethers we will see.
By the way the lexan tether is a great idea and from the pictures I saw it is pretty hard to mess with it, great idea.