This started as a comment over at Goober's place, but I thought I expand it here, as well, since I think it was worth saying.
Goober has made an observation recently that Cliven Bundy is A) Not playing by the Rules and B) actually, properly, and in letter of the law in violation of the lease agreement and therefore has no current right to run cows on the BLM land under question. He has a solid workup on that at his blog.
On the one hand, I think Goober has a pretty solid handle on both property rights and adverse possession. Anybody that gets shirty about that is trying very hard to fool themselves. Adverse possession is pretty solid, established law- if Bundy is arguing that, he likely knows that its not really a valid argument, but it makes a good smokescreen. One thing I should really go look for, though, is how/where his original grazing rights were granted. A good many of these rights were purchased from the Secratary of the Interior prior to the turn of the last century. For example, I know a guy in my hometown whose property includes the original Secretarial water rights that were sold to the Franciscan Order when the area was developed, around 1880 and change. If there's only 5 gallons of water in the creek, he has a claim on it. If Bundy's family has been in continual use of the land since then, he may have a claim, not over the land itself, but over the grazing and water rights. I'm sure the Palouse echoes with the repercussions of the water rights battle in the Klamath Basin and elsewhere; people in the East (very much including people in high rank at the BLM, I'm sure) don't always realize how valuable water is in our semi-arid West. The old saying is that Whiskey's for Drinkin, Water's for fightin over
On the gripping hand, however, its not really about the land, or the cows, or the man; just like the last war here in the States wasn't about slavery, nor the Revolution about tea. When a fight is spoiling, waiting for the drop of a hat, most any hat will do. Cliven Bundy is a rancher, not a Saint, but he has the support of state-level officials, local groups, and he's a more sympathetic figure than Randy Weaver or the Branch Davidians. People saw the BLM acting like Stateist Thugs and called them on it. Despite Bundy's flaws, I think that was a good thing.