(Legally as in, using the legal system)

DOJ sued Deloitte over DEI programs, they ended up settling for $21.5 million: https://www.reuters.com/legal/government/deloitte-pay-215-mi...

Texas Attorney General declared DEI initiatives unconstitutional in a legal opinion: https://www.gibsondunn.com/texas-attorney-general-declares-p...

Several state Attorneys General sent legal threats to 20 major law firms over DEI: https://www.reuters.com/world/us/republican-led-states-deman...

Texas Attorney General warned major banks that DEI programs violate feduciary duty: https://today.westlaw.com/Document/Ibce2fdc5dcec11efb708bbad...

Don't know about corporates, but Harvard was sued[0] for DEI-esque discrimination.

[0] https://en.wikipedia.org/wiki/Students_for_Fair_Admissions_v...

Every statement from company officials such as "we only employ women" or "toxic males", can be used as evidence at court. It is very difficult to prove bias from vague sanitized corporate language, direct "activist" statements make proving such bias very easy. For example recent lawsuit with IBM!

There's a case going through the courts for Red Hat right now where they based managerial bonuses on how diverse their teams were, which reportedly led to them pushing out white males.

Such should rightfully be illegal.