Facebook has ruled out the launch of a new car insurance policy from the UK company Admiral Insurance that would have analysed a customer's posts on the social network to help set premiums.

Admiral has not responded to Ars' request for comment, but The Guardian says of the original plans: "Admiral Insurance will analyse the Facebook accounts of first-time car owners to look for personality traits that are linked to safe driving. For example, individuals who are identified as conscientious and well-organised will score well."

The voluntary scheme would have offered discounts of up to £350 a year.

However, a Facebook spokesperson told Ars:

We have clear guidelines that prevent information being obtained from Facebook from being used to make decisions about eligibility. 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. Our understanding is that Admiral will then ask users who sign up to answer questions which will be used to assess their eligibility.

Section 3.15 of Facebook's Platform Policy says: "Don’t use data obtained from Facebook to make decisions about eligibility, including whether to approve or reject an application or how much interest to charge on a loan."

The Guardian claims to have further details of the kind of tell-tale signs that Admiral's algorithmic analysis would have looked out for in Facebook posts. Good traits include "writing in short concrete sentences, using lists, and arranging to meet friends at a set time and place, rather than just 'tonight'."

On the other hand, "evidence that the Facebook user might be overconfident—such as the use of exclamation marks and the frequent use of 'always' or 'never' rather than 'maybe'—will count against them."

Admiral Insurance already employs another novel approach for gathering extra information about a first-time or young driver's habits in order to set the premium. Its Black Box Insurance involves installing the company's LittleBox in a customer's car, which "collects information about how and when you drive, along with other risk factors to calculate your driving score."

Admiral's new firstcarquote mobile app currently says that "We were really hoping to have our sparkling new product ready for you, but there's a hitch: we still have to sort a few final details." It's hard to see how Admiral will be able to persuade Facebook to change its rules on algorithmic decision making, however, not least because it would create a precedent that other companies would doubtless seek to exploit. A further complicating factor is that Facebook owns a patent that may cover this technique, in the US at least.

The use of algorithms, such as the one that Admiral had hoped to apply to potential customers' Facebook posts, is coming under increasing scrutiny. Last week, the German chancellor Angela Merkel called for search engine algorithms to be made more transparent.

Ars asked the UK Information Commissioner's Office (ICO) for its views on the present case, since Admiral's original plan to apply algorithms to stores of personal data held on social networking sites raises important issues.

An ICO spokesperson said: “The law says that the use of personal information must be fair. A key part of that fairness is ensuring that people are informed about how their data will be collected and used and it is processed fairly. This applies to using personal information acquired from social networking sites. We are paying particular attention to the increasing use of new ‘social scoring’ techniques to ensure that these developments proceed in accordance with the law.”