But a report from The Wall Street Journal indicates that Facebook also saw its Messenger platform as a sIphon for the sensitive financial data of its users.

The data it wanted was anything it could not get unless a customer interacted with, say, a banking institution over chat.

However it all backfired when banks found Facebook's methods obtrusive, but the companies also pushed back against the social network. In some cases, they moved conversations off Messenger to avoid handing Facebook any sensitive data.

Among the financial firms, Facebook is said to have argued with about customer data are American Express, Bank of America, and Wells Fargo.

Facebook was interested in helping banks create bots for its Messenger platform, as part of a big push in 2016 to turn the chat app into an automated hub of digital life that could help you solve problems and avoid cumbersome customer service calls.

Some of these bots, like the one American Express developed for Messenger last year, deliberately avoided sending transaction information over the platform after Facebook made it clear it wanted to use customer spending habits as part of its ad targeting business.

PayPal and Western Union negotiated individual contracts that would let them offer many detailed and useful services like money transfers, the WSJ reports. However big banks in the US shied away from working with Facebook due to how aggressively it pushed for access to customer data.

Facebook told The Wall Street Journal: "Like many online companies, we partner with financial institutions to improve people's commerce experiences, like enabling better customer service, and people opt into these experiences. We've emphasised to partners that keeping people's information safe and secure is critical to these efforts. That has been and always will be our priority."