They're absolute assholes during license audits and negotiations. They're one of only two companies to earn a spot on my "Never voluntarily do business with" list.

And the other?

The other is Verisign, but I am far less passionate and communicative about that one as it was a result of a singular (albeit terrifically bungled) incident, not an on-going and top-down strategy to be a dickish company.

A tad late to the party. You find tons of information about Oracle's business model, which essentially is suing customers.

This report is a good starting point (PDF) [1]

Edited to add : Check the appendix at the end (Appendix – Anecdotal Feedback). It may cure you from the idea of ever wanting to license any Oracle products if you have any say.

[1] http://www.itassetmanagement.net/wp-content/uploads/2014/10/...