The U.S. Justice Department's intensified scrutiny of foreign influence campaigns in the U.S. in recent years has driven an influx of disclosures revealing advocacy for overseas powers and also provided insight into political activity and even the billing rates of some of Washington's largest law firms.

The Foreign Agents Registration Act, a decades-old disclosure law, requires law firms, lobby shops and public relations firms to disclose certain work for foreign countries, and in recent years, as DOJ approached disclosure with renewed fervor, filings have risen.

Indeed, FARA, as the law is widely known, returned to prominence thanks in part to prosecutions brought by the special counsel, Robert Mueller III, including a case against former Trump campaign chairman Paul Manafort.