Bitcoin's rally and posterior collapse are not only taking investors and Financial people attention but also Government and justice department officials in the United States. Regulation has been a high wall that crypto industry has faced in the last years, but also criminal probes like the recently launched by the Department of Justice.\r\n\r\nUS DoJ is investigating 2017 massive rally in Bitcoin price as they are now focused on the use of Tether to prop up Bitcoin. This case is part of a federal investigation of a possible coin manipulation opened earlier this year.\r\n\r\nProsecutors are focused on the use of the popular digital token Tether to drive Bitcoin up. According to the investigation, Bitcoin, Tether and Bitfinex might have been used to move prices illegally as they used Tethers and privileged information to buy Bitcoin at crucial moments when it dropped. They also are suspicious to do spoofing, or placing fake orders to make the price move and then eliminate those orders.\r\nBitcoin Investigation: Bitfinex and Tether again\r\nThe case also highlights that Bitfinex has the same management team as Tether. However, the investigation is not yet clear if they are focused only Bitfinex or also exchange executives for illegal behaviour.\r\n\r\nIt is not the first time Tether, and Bitfinex face regulators as the Commodity Futures Trading Commission subpoenaed both companies last year to prove allegations that Tether coin was backed 1:1 with US dollar reserves.\r\n\r\nTether is used by traders to bet on price moves for other cryptocurrencies, it works like a tradable futures asset, but it is a token that is more stable than other crypto coins.