New York State Attorney General Eric Schneiderman has launched an investigation into crypto-currency trading. The Attorney General’s office on Tuesday sent questionnaires to 13 major exchanges asking who owns them, how they trade and how they charge.

The questionnaires want the exchanges “to disclose information falling within six major topic areas: (1) Ownership and Control, (2) Basic Operation and Fees, (3) Trading Policies and Procedures, (4) Outages and Other Suspensions of Trading, (5) Internal Controls, and (6) Privacy and Money Laundering.”

The Attorney General’s Investor Protection Bureau, under a Virtual Markets Integrity Initiative, is aiming to understand how these exchanges combat “suspicious trading and market manipulation; their policies on the operation of bots; their limitations on the use of and access to non-public trading information; and the safeguards they have in place to protect customer funds from theft, fraud and other risks.”

Regulators across the world have struggled to play catch-up as a horde of technical hitches, robberies and accusations of insider market manipulation have plagued global exchanges. On the hacking side alone, some estimates say crypto trading houses have lost almost $1 billion since 2014.

The Investor Protection Bureau sent questionnaire letters to the US entities of Coinbase, Gemini, bitFlyer, Bitfinex, Bitstamp, Kraken, Bittrex, Poloniex, Binance, Tidex, Gate and Huobi.

The bureau has given the exchanges until May 1 to respond and says it will analyze and compare the different exchanges’ responses and then present its results to the public.