Letters of marque and reprisal would have targeted specific terrorist suspects instead of invoking war against a foreign state. Paul reintroduced this legislation as the Marque and Reprisal Act of 2007. He voted with the majority for the original Authorization for Use of Military Force Against Terrorists in Afghanistan. In April 2009, following the Maersk Alabama hijacking, he proposed issuing letters of marque to combat the problem of piracy in Somalia.
There would be not profit in having a Letter of Marque unless you could commit acts of piracy (A/K/A as stealing other people's stuff) so the idea that they would actually solve anything off the coast of Somalia is laughable, as is the idea they would solve anything anywhere else.