Patent trolls will always exist. I even heard of some folks that apparently patented the idea of an app contacting a server to keep it's data.
Pretty idiotic, but it is a profitable business if you have no conscience.
Blockchain technology should be decentralized and permissionless anyway, so I don't see this as much of a problem.
If a government can stop a cryptocurrency then I don't think it should exist anyway, to be honest.
It stops a certain use of the technology, not cryptocurrencies. In this case the application of blockchain to power consumption optimisation. Any app or project that uses that "method" (is not even a real invention IMO) has to pay Wall Mart.
Is not as much as patent trolls as large companies that instead of using patents to promote innovation, they use them to prevent innovation.