That would probably fall under time or manner restrictions. Most free speech absolutists mean that speech should be free in a way that is independent of content. Time or manner restrictions are generally seen as ok by even most self-identified free speech advocates. The danger and ideological objection is to content based restrictions.
Banning defamation (knowingly making false statements to maliciously cause harm) is a content restriction which is pretty well supported even by serious free-speech folks — at least when the target is a private individual. Defamation of famous people, politicians, corporations, products, etc. is a somewhat less well supported idea.
That would probably fall under time or manner restrictions. Most free speech absolutists mean that speech should be free in a way that is independent of content. Time or manner restrictions are generally seen as ok by even most self-identified free speech advocates. The danger and ideological objection is to content based restrictions.
Banning defamation (knowingly making false statements to maliciously cause harm) is a content restriction which is pretty well supported even by serious free-speech folks — at least when the target is a private individual. Defamation of famous people, politicians, corporations, products, etc. is a somewhat less well supported idea.