Thanks Polyesco.
So Frederik has been doing cycle cross for a couple of years.
It's a sport that is growing here in DK. But it also a sport that is far from appreciated by everyone!
Denmark is a small country, so most of us have a forest or at least a stretch of woodland with comfortable walking-the-dog-distance. Many of these places are also used by people on bikes - some of them have specific tracks used by organized cross country bikers.
The problem is, as it is with almost everyone using the forests, that a few ruin the reputation of others.
Some cross country bikers move around in the forest as if they own the place, without regards to the fact that there are joggers, retirees, birdwatchers, riders, children, dog-owners and what not also in the forests - not to mention wildlife!
And when you have experienced being almost run over by a two-wheeled maniac, you tend to be pretty annoyed!

So some, unfortunately, have gone to criminal lengths to retaliate. Basically sabotaging the paths use by cross country cyclists in particular, in the hope they may crash.
In short: Everybody else can't stand cross country cyclists!
That doesn't mean everybody else are free of blame. Let me mention: People who don't have their dog in a lead, or whose dog is not under control.
Or fanatic joggers running along, unstoppable, with madness in their eyes.
- So especially in the woods in and around the major cities you will find plenty of reasons to hate your fellow human beings.