Blockchain

Hey guys check this article out about block chain, its pretty interesting because from my under standing block-chain was unhackable. Appearently its not https://www.technologyreview.com/s/612974/once-hailed-as-unhackable-blockchains-are-now-getting-hacked/?utm_source=twitter&utm_campaign=site_visitor.unpaid.engagement&utm_medium=tr_social