Moral issues aside (because all patents are enforced by a threat of violence), the problem with patents is that they freeze further development. A prime example was when Hoyle Sweitzer (sic) patented the windsurfer. He made a fortune off of his state/goverment protected monopoly but it put the windsurfing industry in limbo for years because no one could do anything without an expensive license from the Windsurfer company. As soon as his patent ran out the windsurfing market exploded with innovations that reached far beyond the windsurfing market.
On the other hand, I understand wanting to protect something that someone spent years and a fortune developing. I just wish there was a different way. :-)