You might (justifiably) not like it, and it might inspire you to boycott the business or plead for regulatory relief, but it's not an "incident" from their perspective to be intentionally doing what they do to run their business.
This is a bank, and they are regulated. Depending on the information shared, this may be a breach of that regulatory code.
I do not have access to see what the data is, but would certainly in their shoes investigate with high priority, and Would raise a security incident to do so. If it turns out to be empty and of no concern, then great. But ignoring such things is seldom wise.
Might be worth a post on their community.
Re:Off-Facebook activity
by ackshually on Wednesday January 29, 2020 @10:25AM
(#22181497)
What do you mean by community? Like a Facebook community? Do you need an account to post on the facebook community?
They have a Discourse forum: https://community.monzo.com
My bank should send precisely zero things to advertising / marketing companies.
Have you raised it with their Help team? You should.
Unfortunately I cannot as I do not have a facebook account so cannot determine whether or not facebook hold data on me without creating an account.