Data Leak Shakes Notion of Secret Offshore Havens and, Possibly, Nerves

BRUSSELS — They are a large and diverse group that includes a Spanish heiress; the daughter of the former Philippine dictator Ferdinand Marcos; and Denise Rich, the former wife of the disgraced trader Marc Rich, who was pardoned by President Bill Clinton. But, according to a trove of secret financial information released Thursday, all have money and share a desire to hide it.

And, it seems safe to say, they — and thousands of others in Europe and far beyond, in places like Mongolia — are suddenly very anxious after the leak of 2.5 million files detailing the offshore bank accounts and shell companies of wealthy individuals and tax-averse companies.