If everyone is entitled to interact with the internet on their own terms, then why would that not include a service being entitled to act in a way that's adversarial to your desires?
And let's be honest, and I'm the last person to defend FB, but they are not likely to be going to be going after a lone user who has automated something for his own convenience with Selenium or whatever...
Once I decided I wanted to delete a lot of old email from a webmail account. There was no "select all" function so I wrote a one-liner in the javascript console of the browser. When that worked, I automated clicking the "delete" button, and then added a loop to do it over and over. This probably violated a TOS clause somehow, but nothing ever came of it.