@gunfighter: you are wrong in several points:
1) If the constitution is to be taken literally, than a de facto BoA is a violation, no matter how much you'd like it or not.
2) The literal meaning is rarely self-evident. That's where the "living constitution" theory originates from. (And of course the heavy hurdles on amending it)
3) Not piracy induced privateering or LdMs, but vice versa. Privateers are a means of war. Just like a militia. With the exception, that privateers can also get economical benefit from their actions - in difference to a militia, which would then become a gang of bandits or marauders. "Pirates" are those doing the same as privateers just without a valid LdM. And this the reason why it would not work in the case piracy off the Horn. There is no private benefit to be taken and no one to reprise against. Classic pirates were merchant ships that robbed - and so rather all vessels were potential pirates and targets. Somali pirates are no merchant vessels accumulating wealth but small speed boats that kidnap large merchant vessels conduct them to a port and wait for the ransom. Where does in your opinion enter here the concept of prize, war or goods that made the privateer industry work? And for your terrorists, this is called a bounty and people chasing them are called bounty hunters. And this system has to my knowledge been abandoned because it often violated due process rights. But please think straight about what you are talking, esp. when you prefer to take your constitution seriously or even literally.
Also, everybody will get pissed, if you were to reintroduce privateers. privateering is a crime in most states that have laws on navigation, actually one of the most serious crimes. A LdM by the US would not be accepted - as little as other legal concepts. They won't go to war with the US but sack and capture the privateers non the less. Outside of the US, no one cares about the US constitution. A right that one state bestows itself is not equivalent to a right bestowed by international law.
And for starters, criminal offenses are to be dealt with through the judiciary system (that's what it's for, basically) according to the constitution. The legislature should establish the legal basis (what constitutes a crime, what punishments are acceptable, etc.) and the executive should provide the means for doing so. That is the general idea called "separation of powers". To this you can add the system of checks and balances, which was designed to hamper single elements running wild (within their area of jurisdiction) and so to cross-control them.