[throwaway894345]

Defamation, threats of violence, harassment, etc are not free speech, but they are central to Twitter mobs. I would also contend that a concerted petition for an employer to remove their employee constitutes a credible threat since employers often do terminate employees for being targeted by mobs. It really should be only a theoretical question; however, because we ought to have legal protection for employment that would declaw these mobs (especially since the mobs themselves are prejudiced on the basis of race, sex, religion, gender identity, etc--enabling them to have power over an individual's employment constitutes de facto employment discrimination).

EDIT: Downvoters, what do you object to? Do you really think defamation and threats are not free speech? Or do you not think these are cornerstones of Twitter mobs?