Some of their behavior is definitely illegal, and the protesters have zero rights on private property. Go on private property without permission (implied or explicit) and you're trespassing. The property owners do not need a reason to get you out, and need not respect your desire to speak at all. The sidewalk, however, is a public forum, and that's what we're concerned with. Massachusetts' current buffer zone law replaced a more nuanced law that allowed protesters closer specifically because protesters kept doing illegal things. Massachusetts' law is in place specifically because this is a venue where allowing protected speech to be close creates a unique security concern, seeing as how abortion protesters keep breaking the law, threatening and assaulting patients and staff. This isn't theoretical, of course; before the law was in place all those things happened with great regularity. Anyway, nothing stops police from arresting lawbreakers, but the point of the buffer zone is to remove the high probability that the crime will be committed.
My thoughts on this are that this law is clearly legal even though it engages in what in any other circumstance would be unconstitutional viewpoint-based discrimination. I see this as no different than any other police action taken to keep protesters from physically molesting the target of their protest. It's a public safety measure based not on approval or disapproval of a specific viewpoint - which would be unconstitutional in the extreme - but based on the professional judgment of law enforcement and legislators that this type of activity at this present time attracts violent protests that the government has the right - and many would say the responsibility - to prevent.
So the question as I see it is, is this law somehow different from parade security because the law is ostensibly permanent? Does the permanence of the law create a constitutional violation even though the same behavior from police - creating a buffer zone - in response to a specific threat at a specific time would be fine? Or is it not problematic that the law is "permanent" because whenever a court decides it is no longer necessary it will be voided as unconstitutional?
