Facebook has once again been dragged into the firing line – but this time it isn’t the News Feed at fault, but rather the platform’s two-factor authentication system.

Facebook user Gabriel Lewis took to Twitter (ironic, right?) to vent his frustration that the network was using the mobile number he provided for two-factor authentication to serve tailored SMS notifications, without his consent.

So I signed up for 2 factor auth on Facebook and they used it as an opportunity to spam me notifications. Then they posted my replies on my wall. 🤦‍♂️ pic.twitter.com/Fy44b07wNg

— Gabriel Lewis 🦆 (@Gabriel__Lewis) February 12, 2018

There doesn’t appear to be a way to opt out of the notifications, either. Lewis never registered to receive them in the first place, so flicking the toggle didn’t work, and replying to the message automatically posted the response to his Facebook profile.

Related: MWC 2018

The firm is embroiled in a number of class-action lawsuits over violations of the Telephone Consumer Protection Act, which – as noted by The Verge – states that a company is prohibited from contacting you via SMS without first being granted permission.

If Facebook is found to have developed the SMS feature as a way to drive engagement, it could be on the receiving end of a slew of additional lawsuits. As it stands, however, the firm is playing the hoo-ha off as a bug that it’s looking into.

Have you noticed a similar issue? Let us know over on Facebook or Twitter @TrustedReviews.