A Use Requirement for Patent Sales?

According to David G. Barker in the Duke Technology Law Review, in order to prevent patent trolls from deterring innovation and protect legitimate patent enforcers, an open post-grant review should be available as an alternative to costly litigation. Patent trolls should be unable to capitalize on market uncertainty by allowing others to unknowingly develop infringing technologies while waiting in the wings to subsequently appear and extract licensing fees. At the same time, as demonstrated in the previous section, a patentee should be able to sell his patent rights in certain situations and the purchaser should be able to enforce the patentee’s rights. The best way to achieve this balance is to introduce legislation requiring the PTO to conduct an open review of a patent whenever a patent is renewed or sold.

The open review proposed in his article would occur whenever a patent is sold or a patent holder is required to pay maintenance fees to retain his patent rights. The party who purchases the patent would be responsible to pay for the review and the patent holder would have the initial burden of coming forth with some evidence showing "active use and enforcement of the patent."