The US government has started asking foreigners visiting the country under the Visa Waiver Program (VWP) to provide their social media info like Facebook, Twitter and more in a move to spot security related threats.

The VWP is for citizens of nearly 38 countries that do not require a visa for tourism, business, or while in transit for up to 90 days when entering the US. However, they do need to get an Electronic System for Travel Authorisation (ESTA) as a valid travel document, during which time their social media info is sought.

The proposal by the US Customs and Border Protection (CBP) in June had faced months of opposition from tech giants and privacy activists. It got its approval from the Department of Homeland Security just a few days ago. Authorities, however, say privacy advocates need not be worried as CBP officers will only be able to see what's publicly available on the accounts submitted.

The ESTA form now comes with an optional request to "enter information associated with your online presence," and includes a drop-down menu that lists platforms including Facebook, Google+, Instagram, LinkedIn and YouTube, as well as a space for users to input their account names on those sites. Although the info sought is optional for now, given the strict border norms followed in the US, the information is expected to be used to evaluate ESTA applications.

These evaluations will mostly detect safety and security threats and the data cannot be used to ban an applicant's travel based on his or her political views, race, ethnicity, religion or sexual orientation as per the law.