Hate speech from hate groups and from individuals is protected by free speech, so likes on Facebook and other social media websites should be treated the same way. "Liking" something on the Internet isn't a big deal anyway--Internet users can peruse whatever websites they choose, so long as they comply with the site's terms of service.
Liking something on Facebook is a form of expression by someone. If I can go around saying something to someone then why should I not be allowed to do so online? Liking something is nothing more than actually saying it outline it is just a different form of expression. Which is protected under our constitution.