We aren't talking about any law, and we aren't talking about any kind of civil disobedience. We are talking about a single man making a decision devoid of any kind of due process and murdering someone because he disproves of the fully legal if also morally reprehensible actions his victim is engaging in.
Where does it end? Are we then going to endorse the murder of the pharmaceutical executives and researches who've created the morning after pill?
Are we going to advocate and celebrate the murder of the pharmacist who dispenses the birth control pill - after all, depending on what particular philosophical or theological principles you adhere to, birth control is a kind of abortion?
This country has endured this long precisely because we don't allow people to take matters into their own hands, no matter how right they believe they are, or how wrong they believe their opponents are.