In 2006, a hacker going by the name "DerEngel" ("The Angel") wrote a book for respected tech publishers No Starch Press on
Hacking the Cable Modem. The book came with a warning: "The practice of modifying a cable modem violates service agreements, and hackers risk being banned by service providers for life. This book is not intended to be used for stealing Internet service or any other illegal activity." It was intended, you know, for research. Not for stealing Internet access.