You can patent almost anything
In February 2021, the Federal Court of Appeals for the Federal Circuit upheld a district court decision that US Patent 10,075,451 was invalid (see VeriPath, Inc. v. DiDomi, No. 2020-1777 (Fed. Cir. Feb 8, 2021) (see link to Google Scholar). This patent was owned by VeriPath, Inc. and purported to solve drawbacks in the current data collection/privacy schemes. The Appeals Court found that the patent was invalid as directed to an abstract idea -- "exchanging privacy for functionality".