Just to be perfectly clear: the Westboro Baptist Church are a group of bigoted morons who seem to do nothing but harm. The woman who mocked a blind policeman about the attack which disabled him deserves nothing but the deepest contempt. The fact remains, though, that free speech is a protected right for all people. Not just those who we agree with, or even those who the vast majority agree with, but everybody.
Arresting someone on spurious charges is never acceptable, even if she demonstrated herself to be a small minded, offensive moron. Doing so because she behaved in such a way to a police officer is, in a way, worse – not only is it punishing someone for exercising their fundamentally protected right to speech (although she did do so in a profoundly unpleasant manner), it’s punishing her for behaving in such a way specifically to someone in power. A seemingly small thing, perhaps, especially when the vast majority (myself included) would feel the immediate urge to retaliate for her behaviour, but that’s the point: small things are the way that major abuses of power work their way in. If the police can’t be trusted to remain impartial, or, even worse, if the legal system expressly codifies greater protections for certain groups (as in the Pakistan blasphemy situation), the rule of law breaks down – why would anyone accept a system which protects others more than themself, after all?