Bitcoin is a colossal pump-and-dump scheme, which the world has never seen before, says Bill Harris, co-founder of the PayPal payment system.

Bitcoin is a bubble, speculation, and gambling. Bill Harris cracks down on cryptocurrencies with severe crutics in a column, called "Bitcoin is the greatest scam in history", published in Recode.

Speculators specifically create a speculative frenzy around bitcoin, manipulating its price, and then sell their assets at artificially high prices.

According to Harris, bitcoin does not fit into any of the roles that crypto-enthusiasts are wooing.

Bitcoin can not serve as a payment method, because its rate is too volatile and few retailersare ready to accept such payments. "Extreme price volatility" will not allow bitcoin to become a store of value. Bitcoin has no intrinsic value, Harris claims. The growth of its price is explained by the " Greater Fool theory", when every subsequent bitcoin buyer believes that he will be able to sell it at a higher price, Harris continues.

"Dollars, pounds, euros, yen and renminbi are better means of payment, stores of value and things in themselves," Harris believes.

According to him, the cryptocurrency is best suited for only criminal activity.

"Because transactions can not be anonymous - law enforcement can not easily trace who buys and sells - its use is dominated by illegal endeavors."

Harris does not stop and calls most of bitcoin users "criminals" who are either involved in frankly illegal transactions or using bitcoin to evade taxes.

He recalls that it were cryptocurrencies that were involved in Silk Road and WannaCry ransomware, that crypto-exchanges are susceptible to hacker attacks (for example, cases with CoinCheck or NiceHash mining pool) or are fraudlent themselves (for example, Mt. Gox or Bitfunder).

"Way too many Initial Coin Offerings are scams - 418 of the 902 ICOs in 2017 have already failed."

Harris writes that he would simply laugh at frenzy around cryptocurrencies, but they jeopardize innocent people.

"But ordinary people are investing some of their life savings in cryptocurrency. One of the brokerage is encouraging its customers to purchase bitcoin for their retirement accounts!" Harris writes indignantly.

He completed the column, urging US regulators to protect ordinary retail investors from fraudulent schemes.