In launching the policy, dubbed firstcarquote, Admiral argued that there's a "proven link" between personality and how people drive.

"It's scientifically proven that some personalities are more likely to have an accident than others. But standard insurance questions don't tend to measure personality," says the company. "At firstcarquote, we look at a driver's personality by analysing some of their Facebook data and if we see indicators that you will be a careful driver, we will give you a discount of between 5 and 15% off the price you would get on admiral.com."

The firm's firstcarquote page doesn't go into further detail, but according to the Guardian the insurer's algorithm examines posts and likes by Facebook users and searches for traits that identify applicants as conscientious and well-organised. This includes writing in short clipped sentences and using lists, while over-use of exclamation marks will score a black mark.

Although the firstcarquote page is live, the company has been forced into a u-turn after falling foul of FaceBook Platform rules on subscriber privacy.

In a statement, Facebook says: "We have made sure anyone using this app is protected by our guidelines and that no Facebook user data is used to assess their eligibility. Facebook accounts will only be used for login and verification purposes."

Now, drivers will be able to log onto the Admiral app via Facebook before answering questions from the insurer - all of which could still lead to a discount.

"Following discussions with Facebook the product is launching with reduced functionality, allowing first time drivers to login using Facebook and share some information to secure a faster, simpler and discounted quote," Admiral says.

Privacy advocates Open Rights Group welcomed the decision.

“We need to think about the wider consequences of allowing companies to make decisions that affect us financially or otherwise, based on what we have said on social media. Ultimately, this could change how people use social media, encouraging self-censorship in anticipation of future decisions," says ORG executive director Jim Killock. “Young people may feel pushed into such schemes because of financial constraints. The right to keep things private shouldn't be the preserve of those who can afford it.”