Concerning which, a few things:
(1) Killing the abortionist, like any other form of privately killing a killer, is unacceptable. One of the relatively few legitimate functions of government is to punish criminal conduct through due process of law; such punishment by private hands, without such due process, is clearly wrong. Whoever has killed Tiller should be punished accordingly (through the due process of the law). The fact that the state has spectacularly failed in its duty with respect to Tiller and his many colleagues in the death business does not justify a private execution. That failure does justify the overthrow of the ne'er-do-well government; but, then, that failure is just a single element in a vast and continually-growing collection of such justifications. Overthrowing a government isn't easy; governments tend to make it as difficult as possible, for the obvious reason. But that's outside the scope of an Obligatory Tiller Murder Post.
(2) Tiller was, I suppose, an attractive target for violence in that he was a symbol of the extreme. I note here that the very-late-term killings for which he was famous (well, notorious is more like it) are no worse than the "standard" first-trimester grind-'em-outs that are the main grist for every abortion mill. What distinguished Tiller was his special intransigence. Imagine ten men who make their livings clubbing baby harp seals to death for their fur. Nine of them just dully club every baby seal that comes along; the tenth gathers the very cutest ones, the ones with the biggest eyes, and bashes them. There's no real moral distinction there; "a person's a person, no matter how small." It's just a matter of style points. Again -- sigh! -- style points don't justify murder. I merely note that, unless one is courting some kind of diabolical martyrdom, one would be well-advised to be a little less in-your-face about one's misdeeds.
(3) As I type this, the world has about 6.78E+09 people. The annual death rate, worldwide, is estimated at 8.6 deaths per thousand people. Statistically, then, about 159,643 people died last Sunday. Of those, 159,642 are a greater occasion of sorrow than one George Tiller, late Kansas abortionist.