Inc. had been haggling with financial firms over its access to
users’ sensitive financial information for years, well before
the social-media company came under fire for its handling of
recently as last year, the social-media company pressed
financial firms for the ability to use customer data flowing
through its Messenger platform for a range of purposes,
including advertising, according to people familiar with the
matter and documents reviewed by The Wall Street Journal.
Concerned about privacy,...