But epeeist, surely you're not suggesting that an amount of distress has been measured (somehow) that is worth something in the area of 11 million dollars? That had the Phelps' not protested this funeral, the improvement in the father in question's current life or mental state would be worth US$11,000,000?

Either way, when speaking on matters of communication and expression, the consequentialist notion of "you did damage, pay for it" starts to weaken when the 'damages' are not, in fact, easily 'measured', and the resulting 'damages' are not so reliably contingent on the 'attack' in question as in the case of physical assault.
A good rule of thumb I have always employed is, it is unethical to knowingly hurt the feelings of others when there is nothing to be accomplished by doing so, but making it legally punishable to hurt someone's feelings is to move a little too close to a kind of 'emotional fascism'.