A new appeals court ruling, which found that parts of Oracle’s Java API set are entitled to copyright protection,may show why many cloud providers hesitated to support Amazon(s amzn) Web Services APIs from the get-go.

In theory it made sense for them to adopt AWS APIs because AWS was (and is) the market leader in public cloud, so offering some degree of compatibility with it would make sense for all the newcomers. But that assumed that the use of those APIs is not legally problematic.

Well, guess what? The use of another company’s APIs has become problematic since the Federal Circuit Court in Washington, DC found that Oracle(s orcl) could indeed assert copyright over 37 APIs — reversing a lower-court finding that API’s are not subject to copyright since they are an idea, not a creative expression.

In the four-year-old case, Oracle claims that Google infringed on various Java copyrights in building its Android smartphone operating system. Google has not said…