No good. First of all, any killing is cruel. And other than the
killing of the lobster by the butcher, the customers will also
share karma for this by ordering it, because it is ordering it to
be killed. Secondly, by witnessing the killing of our food, also
makes the meat impure.
Five Clean Sources of Meat (article)
...Buddha understands the
ignorance and habits of sentient beings that have accumulated from
aeons of their many past lives. In order to provide sentient beings
with an expedient means of embracing Buddhism, those who are not
able to convert to a vegetarian diet on a long term basis are
permitted to consume meat provided:
(1) That he did not slaughter the animal personally
(2) That he did not instruct others to slaughter
(3) That the slaughter was not committed for his sake
(4) That he did not witness the slaughter
(5) That he did not hear the cries associated with the
slaughter...
That is why ordered seafood is not Pure Meat. Frozen meat can at
least be considered 'clean meat' -- it is not direct killing, so
the karma is not so strong. Nevertheless it is still killing so
being vegetarian is best. But not everyone wants to be a
vegetarian, so the least is we must try eat only the 5 clean meat.
I myself try to abide by this, as I am not a vegetarian.