Around 50% of the US is federal land. There has long been a theory that they have leveraged the land (or the resources on it) as collateral to obtain loans from China.
It could be that they need to completely free up the land to eliminate ownership and use rights questions. That could be one reason for targeting all of these ranchers.
There was a rumor awhile back that Hillary Clinton offered China the rights to execute eminent domain proceedings in the US, but I don't believe things have progressed that far. I'm more inclined to believe it involved federal land and not private.
http://www.libertygunrights.com/Crit...entDomain.html