According to legend (I wasn't actually there - this is secondhand, so do take with a grain of salt), they tried to convince a company I worked with previously that they needed an additional license for the server that processed backups. No Oracle client or server installed; the logs were pushed via ssh. When they balked, Oracle tried to increase the price two more times. It was apparently great motivation to move to MySQL.
Maybe that was just one particularly bad rep, but I don't think I've gone through a single year of my career without hearing something absurd about them.
A contract was signed and during early implementation Oracle EOL'ed a significant module with a replacement that was planned but did not exist. Followed by attempts to charge us for their development of the replacement which, again, had been a pre-paid module in their off-the-shelf ERP. Already paid for.
That didn't fly, but later the replacement lacked key features: A web-facing portion collected information. We demo, it works, we ask where data processing folks view it in the forms app... crickets. Conversation ensues:
O: "It's in the database"
Me: Sure, but where do users view it when collating the other information?
O: "Well, a dba can get to it"
Me: Okay, but when we go live, will it show up as a another tab in a form or...?
O: "We've completed our build of this feature"
Me: Hold on, collecting & processing this data is a critical and contractually itemized deliverable. You have developed half of that deliverable.
O: "We've completed out build of this feature"
I was probably fortunate that my CIO was there, and took over at that point. A few weeks later, Oracle walked off the job. There had been delays in a modules I wasn't involved with, and Oracle wanted more money. It was a fixed-price contract, and we wouldn't re-open negotiation on a signed contract already multiple milestones in on its payment schedule. Oracle walked. Literally gone, no word, no message, just dozens of people that were there on Tuesday, gone on Wednesday. That's Oracle.
There are more choice quotes in someone else's HN comment about Bryan Cantrill on Oracle.[2] I highly recommend any talk you can find of Bryan Cantrill. A wonderful mix of industry history and great delivery.
Also, their (re)licensing process for existing customers pretty much amounts to extortion. You better be really sure about how much it would take to rewrite your systems without Oracle, have a plan how it would be done, and advertise it to them - because as soon as they'll feel a lock-in, prepare to open the wallet for ridiculous sums for trifling things that you've been doing for years for free, but now their lawyers can find an weird interpretation where that requires extra licenses; they don't even attempt to increase the revenue by providing some extra value or service for you but simply by applying their muscle.
It's not pure capitalism, which would provide mechanisms for dealing with this, and it's not too much regulation, which could also prevent this, it's just the right amount of both that allows Oracle to play them against each other to game the system.
I sat outside the door of the CIO's office. He wasn't expecting anything shocking and so left the door open during the call. Oracle had previously told us that we wouldn't have to pay for licenses for non-prod instances. When they went back on that promise, the CIO said (well, shouted) "Okay, fine! Tell me how much you're going to fuck me. As soon as you're done with that, I'll fuck you right back by throwing Oracle out of my datacenter!"