This says they are[1]: Interoperability has been succesfully used as a fair-use defense in the past, and commercial use decreases the chances of a fair-use ruling. Both points (interoperability and commercial use) are central to the Oracle v. Google case, and have been brought up by both sides. See here[2]:<p><i>I reached out to Collard, a partner at Dorsey &amp; Whitney, who specializes in intellectual property... &quot;In my opinion, the biggest problem for Google is the commercial nature of its use [of the APIs],&quot; he said. &quot;That is generally a strike against finding fair use. Its best argument is probably interoperability -- in other words, it should be fair use because Google must use the APIs in order to make its products interoperable.&quot;</i><p>[1]: <a href="https:&#x2F;&#x2F;www.cs.duke.edu&#x2F;courses&#x2F;cps182s&#x2F;fall02&#x2F;cscopyright&#x2F;Copyrights&#x2F;Copyright-Fairuse.htm" rel="nofollow">https:&#x2F;&#x2F;www.cs.duke.edu&#x2F;courses&#x2F;cps182s&#x2F;fall02&#x2F;cscopyright&#x2F;C...</a><p>[2]: <a href="https:&#x2F;&#x2F;adtmag.com&#x2F;blogs&#x2F;watersworks&#x2F;2015&#x2F;07&#x2F;google-java-apis-fair-use.aspx" rel="nofollow">https:&#x2F;&#x2F;adtmag.com&#x2F;blogs&#x2F;watersworks&#x2F;2015&#x2F;07&#x2F;google-java-api...</a>