Although the first might be to some people acceptable, and we can discuss at length what it involves, why it might even have aesthetic value, the second is purely trash - Farrell's case, and artistically speaking, his work is also very low quality.
They are not just of erotic but also of artistic and historical value.
BDSM is in great part what makes gives all depictions of sex and erotica a bad name, a verboten subject.