Guardian article on taking on Sainsburys and Asda for equal pay.
As someone who had to threaten to take my then employer to court (eventually settled through ACAS, in my favour), this is close to my heart.
I'm not allowed to discuss the details of my case (gagging clause) but it was the result of "cock up" rather than "conspiracy" - long pay scales and long time to reach "target rate for the job" meaning that women's pay slowly but inexorably drifted away from men's pay after a couple of periods of maternity leave and a nominal "okay at your job" mark for performance.