Who: BlackRock Inc.

# of Accounts Breached: More than 12,000

What was affected: Names and email addresses of financial advisers who buy BlackRock’s ETFs on behalf of customers.

When it happened: December 5, 2018

How it happened: BlackRock Inc., the world’s largest asset manager, inadvertently posted confidential information about thousands of financial adviser clients on its website. The data appeared in three spreadsheets, linked on one of the New York-based company’s web pages dedicated to its iShares exchange-traded funds. The documents included names and email addresses of financial advisers who buy BlackRock’s ETFs on behalf of customers. They also appeared to show the assets under management each adviser had in the firm’s iShares ETFs.

Outcome: The documents were seen by Bloomberg and removed Friday.