We haven't really figured out how to address these issues. The best we've got now is an initiative by Metro called Viralgranskaren (~"viral post inspector") that debunks myths like these. [1] What I think needs to happen is for the education system to start putting a larger emphasis on skepticism and source criticism. These skills and qualities are crucial for a 21th century liberal democracy.
[0]: http://www.snopes.com/sweden-bans-christmas-lights/
[1]: http://www.metro.se/nyheter/viralgranskaren/ (sadly only available in Swedish, it seems)
This isn't a problem in Swedish and Danish, as their infinitive marker is "att/at", which in Norwegian only means "that" in its conjunctive form.
I wonder if there's any relation to the Norwegian here.
https://en.m.wiktionary.org/wiki/att#Swedish