Two Evil-isms, Pinkertonism and Anarchism

Charles Angelo Siringo (1855-1928) was an author, detective, bounty hunter, lawman, and cowboy (not necessarily in that order) who worked for the Pinkerton Detective Agency from 1886 to 1907. As you may have guessed by the title of the book, Siringo and Pinkerton had their share of run-ins.
Siringo wrote his first book, and autobiography, just before his career with Pinkerton, to great acclaim. More than 20 years later, in 1912, he attempted to write another loosely autobiographical account of his time with the Pinkerton Detective Agency. The Agency made him omit their name from the book as well as his references to working for them, citing the confidentiality agreement between Pinkerton and its employees upon hiring.
A smear campaign by Siringo ensued, culminating with the publishing of Two-Evil-isms. Pinkerton sued him for criminal libel.