Sen. Elizabeth Warren and six other members of the U.S. Congress called on leaders in Texas to disclose the energy usage and environmental impact of Bitcoin mining operations in the state.

What Happened: Warren (D-MA) sent a letter to the Electric Reliability Council of Texas and its CEO Pablo Vegas.

In the letter, Warren accused Texas of being a “deregulated safe harbor” for crypto mining firms. The letter said Texas offered “cheap power” and relaxed regulation which could cause stress on the energy of the state, as reported by Decrypt.

Warren asked for information to be turned over that includes how much electricity Bitcoin BTC/USD miners in Texas consume and how much carbon dioxide emissions they have been responsible for over the past five years.

“In simple terms, the Bitcoin miners make money from mining that produces major strains on the electric grid, and during peak demand when the profitability of continuing to mine decreases, they then collect subsidies in the form of demand response payments when they shut off their mining operations and do nothing,” the letter read.

The letter called for information on how much the mining companies were paid in subsidies.

One specific company named in the letter was Riot Blockchain Inc RIOT, which has a facility in Rockdale, Texas. Riot Blockchain said in July it made $9.5 million by shutting down its operations and selling electricity back to the power grid.

The letter asked for full transparency and…