Travelling these days means you have to hand over a large amount of data about yourself at borders, for security reasons and for surveillance.
It's hard to argue against it because who doesn't want to contribute to stopping terrorism, but at what point are the authorities asking for too much information?
There's a proposal currently by the United States Department of Homeland Security to ask travellers to the country for their social media presence, like their Twitter and Facebook handles.
The reason for that proposal is the DHS wants to see if you've been saying bad things or hooked up with undesirable people.
"Collecting social media data will enhance the existing investigative process and provide DHS greater clarity and visibility to possible nefarious activity and connections by providing an additional tool set which analysts and investigators may use to better analyse and investigate the case," DHS believes.
What that means exactly remains to be seen.
Obviously, "nefarious activity and connections" such as supporting islamist terrorist crazies on social media would be noted, although you'd think that's being done already.
What if Donald Trump actually becomes president of the United States and decides that the Scots who responded rather robustly to his inane comments about Brexit on social media shouldn't be allowed into America?
It's very easy to construe what's said on social media whichever way you like, and take umbrage, or see it as a threat. A travel preventing threat even.
The proposal says the field on the paper and electronic arrival records for travellers would be optional to fill out. Like all "optional" fields, not filling it in or refusing to do so would make border agents suspicious so good luck with not handing over your @-handle to them.
Now, he point of registering people's social media presence is only partly to observe what they say online. Being able to capture metadata such as the location and time of postings, who people speak to and mapping their social media connections, is equally valuable.
You might think that all is fair in the war against terrorists who are very adept at using social media for propaganda and recruitment, and that average people have nothing to worry about.
Think again: this is the internet we're talking about, and social media is far from secure.
Even SuperGeeks such as Google boss Sundar Pichai, Twitter's Ev Williams and Facebook founder Mark Zuckerberg make mistakes and have their Pinterest, Twitter, Quora and other social media accounts compromised.
They either forgot to shut down unused social media accounts, or re-used or had very simple passwords, and are now sitting there with red faces after being hacked.
If your social media presence becomes one of the deciding factors for travel, you had better make sure those Twitter and Facebook accounts are as secure as possible because they could be targeted and used against you or your business.
How many social media providers will you have to list?
Most people I know who use social media have accounts on multiple providers - and sometimes several accounts on each. (If you don't use them, delete the accounts; see above for the reason why.)
How about deleting your social media accounts then? Try and see if they believe you at the border when say you're not on social media, especially if you fall into a certain age group and have a smartphone.
Ultimately, the additional social media information capture will most likely be useless for the authorities. Bad people will create new or fake social media accounts, or even use someone else's handle.
Sadly, Sir Tim Berners-Lee who helped build the world wide web and others around him are right. With the internet, we have created a global surveillance machine.
Berners-Lee wants to redesign the web for privacy, less control and more creativity and free speech, and evading censorship and repression.
Here's hoping Sir Tim the old 'Net subversive didn't say that on social media, as he might not be let into the States again if he did.