How are you going to negotiate without striking (or threatening a strike)? Why would the company care that you know you're being underpaid if you're still going to do your job either way?
You’re going to negotiate with the knowledge in par with the company that is interested in having you.
Knowledge is power. - France is bacon.
Unless companies conspire not to hire you in order to depress wages.
https://variety.com/2017/biz/news/disney-settlement-wage-fix...