[neolefty]

I'm new to the details of Bitcoin, but I found these explanations to be illuminating:

Bitcoin relies on agreement among peers on a single unbroken chain of blocks: https://en.bitcoin.it/wiki/Block_chain

It takes computation work (searching for a header that produces a hard-to-find hash value) to generate the next block. Therefore, the block chain can be taken over by someone with 51% of all the hashing power on the network because the peers agree on whatever chain reflects the most work: https://en.bitcoin.it/wiki/How_bitcoin_works#Double_spending

In order for a bitcoin transaction to be consummated, it must be encoded in a new block. The entity that generates the block chooses which transactions to include in the new block, and the 15% entity that is the subject of this article is not including any transactions. Instead, it is only awarding itself the standard bounty for discovering a new block.