By now you should be reading chapter 4, the last two sections on patents.
Apple in patent trouble? arstechnica.com/tech-policy/2018/04/apple-ordered-to-pay-502-6m-to-virnetx-after-jury-finds-patent-infringement.
https://www.computerworld.com.au/article/628449/us-deputy-ag-attacks-warrant-proof-encryption/
encryption and copy protection