Hi,

ech, bitcoin: http://qntra.net/2016/03/a-miner-problem/

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - That the notion of "a majority of Bitcoin nodes" is void of content, most of the relay network being under the control of the same entity and supporting functionality not contemplated by the Bitcoin protocol (such as selective mothballing of specific transactions). This specifically means that "someone" has the ability to nuke transactions out of the network irrespective of whether they are validly signed or not, directly replicating functionality already available to fiat governments in fiat payment processors such as Visa or Paypal.

That a cartel of Bitcoin miners is deliberately and systematically withholding blocks for an interval of about 20 minutes to a half hour, so as to ensure themselves a (significant) advantage over any would-be competitors.

That neither above item makes sense or could long survive without the other, meaning that necessarily the culprit is one and the same. Note for the record that an entity controlling 51% of the network (as is by a large margin the case with the Antpool/F2pool cartel) can safely withhold blocks for an indefinite period – if a competitor publishes a longer chain all the cartel has to do is keep mining on its own, eventually they'll prevail. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -