Being fired
The employer could fear a lawsuit, bad reputation, demotivated co-workers and so many other things. Start by requesting a huge severance package. You will likely not get it but try for much more than the legal minimum (or nothing). Be flexible in negotiating and close the deal as soon as possible. Forget threatening the person on the other side of the table or the company. Maintain your good standing for you never know what you may need from them later on.