You can't use the remote APIs you need to deliver the same local APIs that are required to run modern apps without spoofing the signatures of applications - otherwise google's remote APIs would forbid access. This is where security measures are also inherently DRM-ish, and to deliver the experience typical end users expect using free software (free-er than stock android) it's necessary to circumvent it. One could argue that such circumvention is illegal. I hope no one deems it to be so.