In the 90s (the 90s!) Mobil provided domestic partnership benefits for its employees, and when Exxon bought them in ‘99, those benefits went away. Earlier this year, ExxonMobil employees started an effort to get a nondiscrimination policy to cover sexual orientation and gender identity and this effort was fought by the corporate offices and eventually unsuccessful. Shareholders held a vote and agreed not to adopt this policy.
Also, they refuse to admit responsibility in the Exxon Valdez oil spill in 1989.