Updated February 19, 2018 13:40:18

Photo: Facebook will send out postcards to those wanting to buy political ads in the US. (Reuters: Dado Ruvic)

Facebook will soon rely on centuries-old technology to try to prevent foreign meddling in US elections: the post office.

Baffled in 2016 by Russian agents who bought ads to sway the US presidential campaign, Facebook's global politics and government outreach director, Katie Harbath, told a meeting of the National Association of Secretaries of State in Washington on Saturday that the company would send postcards to potential buyers of political ads to confirm they resided in the US.

The recipient would then have to enter a code in Facebook to continue buying the ad.

The method will first apply to ads that name candidates ahead of the midterm elections in November, said Facebook spokesman Andy Stone.

The plan was unveiled a day after special counsel Robert Mueller charged 13 Russians with interfering in the presidential election.

Mr Mueller's indictment described how Russian agents stole social security numbers and other information from real Americans and used them to create bank and PayPal accounts in order to buy online ads.

Agents also recruited Americans to do things such as hold up signs at rallies to create content for Russian-created social media posts.

Social media monitoring apps reveal the extreme levels of smart phone use.

Facebook uncovered some 3,000 Russian-linked ads on Facebook and Instagram bought before and after the November 2016 election that it says may have been seen by as many as 150 million users.

Ads only part of the problem

But ads were only part of the problem. The Mueller indictments say Russian agents also set up fake pages with names such as Secured Borders, Blacktivist and United Muslims of America that had hundreds of thousands of followers.

Facebook did not say how the new postcard method of verification would prevent foreign agents from setting up local mailing addresses and hiring people in the US to check them.

But Mr Stone said the method was "one piece of a much larger effort to address foreign electoral influence on our platform."

Facebook's efforts largely centre around verifying that people on the platform are who they say they are.

To catch duplicitous ad-buyers, for instance, it is now testing out in Canada a system that allows people to see which ads are being bought by a Facebook page — say, a candidate's — even if the person checking the ad is not in the group to whom the ad was intended to be shown.

Mr Stone said Facebook was also able to detect and remove "tens of thousands" of fake Facebook pages ahead of elections in France, Germany and the UK last year, using improved machine learning techniques.

The company has said it will double the number of people working on its safety and security team to 20,000 this year and add 1,000 people to review advertising content.

AP

Topics: internet-technology, computers-and-technology, science-and-technology, united-states

First posted February 19, 2018 13:26:06