I wonder when it will start doing the same (overtly anyway) from US citizens and visitors.
edit: Actually Dec 2016 / Jan 2017 https://www.theverge.com/2016/12/22/14066082/us-customs-bord...
> Enter information associated with your online presence, including the types of online platforms, applications and websites that you use to collaborate, share information, and interact with others, as well as the username(s) associated with those accounts. (OPTIONAL)
With the length of time and the amount of sites I use I'd be here hours filling this in. I love NYC and have family in the states but I really can't imagine willingly going there now. Though the UK is hardly going the way of anything better.