[shreyansj]

I am actually curious how you would go about proving that you are a citizen of the EU. I am sure you need some form of identification to board an international flight even though it might be within the Schengen area.

[vertex-four]

So, from experience squatting in the Netherlands... nobody bothers to check, unless you look like you might be from Eastern Europe or outside Europe, at which point they throw you in a foreigner detention centre until you can prove your identity or they can deport you to wherever they think you might be from.

[Tade0]

My experience driving through the EU is that barely anybody cares. You may be stopped at internal borders if your car plates don't match a Schengen-area country, but that's it.

You'll need your ID to stay in a hotel/AirBnB though. So unless you squat or camp illegally, better have it with you.

[vertex-four]

Plenty of places within Schengen where wild camping is legal, and couchsurfing (through platforms other than couchsurfing.com) is still a thing.

[msh]

It seems to depend. I have never been asked to provide id when flying SAS with a business ticket between denmark and sweden or finland.

[clan]

That would probably be due to the Nordic passport union[1].

Locals have been able to travel between the countries freely without a passport since 1954.

[1h] https://en.m.wikipedia.org/wiki/Nordic_Passport_Union