Facebook is unable to tell if you are a bot or a human based on your mouse movements... They don't follow mouse movements at all. The overhead for this would be so large that they would need 100x the processing power they have at the moment.
You can access any page on facebook any time, they don't have any protections in place that look at the succession of your actions. In fact, such protection is fairly easy to implement and will effectively kill 99% of the automation software currently available. However, it will be an overkill in terms of processing. This seems like the only logical reason they are not doing it.
Creating a bot that would just cycle through accounts, login with each account and like a page, changing proxies per 10 accounts or so, is very easy to do. However, non-pvas are usually required to solve captchas every time they like a page.
