In recent months, federal prosecutors have issued subpoenas targeting Russian oligarchs’ assets in the U.S., such as real estate, cash accounts, and trust funds. Since February, Western authorities have frozen more than $330 billion in Russian assets held in foreign bank accounts, trusts, yachts, jets, real estate, and jewelry. Prosecutors face many hurdles in their efforts to uncover the assets. Oligarchs transfer their assets into trusts or shares held in layers of companies and multiple jurisdictions.