At least the president's appropriation of power to summarily kill Americans is extra-legal. It hasn't been codified or approved by any other branch of government. In justifying assassinations, Obama can't invoke any congressional or judicial actions; he can only repeat Richard Nixon's infamous maxim: "If the president does it, it's not illegal."
So it's not surprising to learn that the Obama Administration has considered establishing a special, secret court to authorize targeted killings. Modeled after the FISA court, which authorizes national-security-related domestic surveillance, a Targeted Assassinations Program (TAP) court -- my name for it -- would provide judicial cover for the president's actions without providing substantive judicial review.
"Having the executive being the prosecutor, the judge, the jury and the executioner all in one is very contrary to the traditions and the laws of this country," newly elected Maine Senator Angus King asserted, in support of proposals for a TAP court. But in essence, the executive would remain prosecutor, judge, and jury, even if the law required a little judicial approval.