Quote from: Odalv on June 21, 2015, 08:54:15 PM

With 10,000x as large chain ordinary user cannot verify if block is valid. If there are only last 5 big miners left then they can start to produce fake block. b/c there is nobody (except 5 miners) who has enough resources to verify all blocks.

According to the "high growth rate" curve in the graph above, the blockchain will be 10,000x as large in 2035. Here's a quick estimate of some of the costs to run a node twenty years from now, assuming no change in the cost of disk space or Internet bandwidth for 20 years.

Even under these (a) optimistic growth rates, and (b) extremely pessimistic cost improvements for disk space and bandwidth, the cost is still not so prohibitive that there would only be "5 big miners left." For example, I'd image that all major research universities, bitcoin corporations, various branches of governments, and power users (whales) would still run nodes (1000+ nodes). The network could actually be more decentralized than it is now.

Quote from: Odalv on June 21, 2015, 08:54:15 PM

Everyone must verify everything is bad design. => this will collapse.

Only full nodes need to verify everything. Not every user needs to run a full node.

Why do so many people equate users with full nodes?