If you are planning to sue somebody because you are angry and it has become a matter of principle then it's a Big Fail!

There is no point in suing anyone as a matter of principle. The only reason to sue somebody is because you are going to win and because you are going to get some money out of it.

If you are suing because it has become a matter of principle then you should go and have a drink and try and relax and think whether it is really worth all the trouble. If there is a chance that you're going to lose the case then give it up.
Imagine the humiliation of your principles if the person you are trying to score against ends up winning and you then have to pay your own costs and maybe some of this.

If you are suing somebody because it has become a matter of principle then you will be much better off going round to their house, slapping them in the face with your glove and then challenging them to a duel.

That is the only way to settle matters of principle.