When I look at this more recently, the conclusion still seems to be valid: we'll run out of 16 bit ASN's somewhere in 2011 to 2013. There are a lot of unused ASN's out there. Recovering them will postpone the problem by a few years but it won't solve it. The basic problem with recovery is how to decide if an ASN is really no longer used/needed. There is (still) no mechanism to do this.
sounds a lot like IPv4 space, eh?
Why not go after low lying fruit first? If an ASN was assigned years ago and hasn't appeared in the RIB for the past year that ASN should be reclaimed. Send warning emails to the registered contacts as well as to the assigning LIR and after 3 months - just reclaim it.
because property is unused publicly does not affect the rights of its owner(s). otherwise old car collector wannabes could have a heyday. perhaps the world would be a better place if we spent less energy on net vigilanteism and more on moving to IPv6 and 4-byte AS numbers. randy