I was at first stunned then amused when I learnt of the concept of "privilege checking". Conceptually it's a hierarchy where under-privileged groups are granted privileges based on how under-privileged they are - all in the case of equality.
For example if someone is being abusive and you respond in kind, then you must check your privilege. If you rank higher on the privilege hierarchy, then you are expected to apologize to the under-privileged because your anger was a defensive reaction and an attempt to prevent debate while their anger is justified by being part of an under-privileged class:
If someone suggests that you're doing something racist, ableist, etc., you will tend to react defensively. That's OK and natural! Take a deep breath, check your privilege, step away from the keyboard if you need to, then apologise and figure out how not to do it again. If you continue to think the person misunderstood you or was wrong about your actions, don't get into an argument with them about it. [link]
Likewise it's perfectly acceptable for the under-privileged to have their own private spaces but unacceptable for the privileged to have the same. So while male only gyms or social clubs are unfairly excluding the under-privileged, female only social clubs are acceptable because the under-privileged need the privilege of talking about under-privilege without the privileged being around to sidetrack the debate with their privilege:
Contrary to popular belief, spaces for minorities only aren’t the same as spaces for privileged groups only. For the most part, it’s not about excluding but rather having a space to address our issues without told that they just aren’t as important as “real” issues. Since privileged groups have the privilege of being the “default” person (whether it be default gender, race, sexual orientation, etc), “default” spaces are naturally focused on them. In a nutshell: minority spaces are needed because they are the only place where non-privilged people can truly focus on our own issues. [link]
I would continue with this absurdity but I just checked my privilege and you better believe that mocking lefty feminists is a privilege I don't have. But as a final word, the identity politics of the left is crippled with an equivocation between egalitarianism and hierarchies of privilege. It is incoherent to construct hierarchies of privilege in the name of egalitarianism.