I dealt with one that seemed actively hostile. They would change their API without any advance warning at all. Data fields that we depended on would mysteriousl

I dealt with one that seemed actively hostile. They would change their API without any advance warning at all. Data fields that we depended on would mysteriously vanish in the middle of the day, causing our entire system to grind to a halt until we put in a hotfix. Happened several times in the two years I worked on that project.