If any of you have travelled to the USA in recent years you will be aware of the Electronic System for Travel Authorization (ESTA) application process. The ESTA provides citizens of the 38 countries that are part of the US Visa waiver programme pre-travel clearance for travel to the US, 'Visa free' for periods up to 90 days.

The ESTA requirement is a bit annoying and really is a mini-Visa under another name, as the application isn't so rigorous, and it isn't nearly as expensive as a full-blown Visa (it costs $14 at time of writing). When/if your ESTA is approved, and you need it before you begin your journey, it covers you for two years.

Recently the US Customs and Border Protection Agency requested that some questions be added to the ESTA form to help them filter people coming in to the USA. The requests were approved on 19th Dec and now, as Engadget reports, the changes have been implemented in the ESTA online form.

As you can see above, the Social Media section of the ESTA form is 'optional'. Many people will fill it in to avoid potential delays and hope to minimise the already lengthy process of getting off a plane and heading to their desired end location, looking forward to staying with a friend, family or at a nice hotel, for example. At the current time it's not really known if or how people who skip the optional section will be treated differently.

A wide range of social media site IDs are listed in the form. Among the obvious Facebook, Twitter, and Google+ entries are some I haven't heard of, plus there is an 'other' entry option too.

Various organisations and news sites have voiced worries over the possible invasion of privacy the social media probing might result in. Furthermore, some think there might be a security domino effect where other countries start to request social media information.