ok ok ok...
I thought you all guys should say something like "Bears, Moose or idk Angry Birds".
BUT, the actual answer is:
Because they carry TBE-virus AND the bacteria Borrelia. So TBE can cause Sever Brain-damage (like Brain-diseases) and it can actually be lethal for elderly people and weak people (like people with weak immune-defense). You can protect yourself from this by taking a Vaccin (so I mean, there is protection). And Borrelia, you can't protect yourself from (unless you are really fast "take quick actions and notice it very quickly") and it can cause all kind of annoying problems like: Throw-ups, Fever and spasms (I think at least).
So it's basically "Double-trouble".
And they exist everywhere in Sweden (because they are so small, and live in the nature). So if you are going for a walk in the nature, be sure to have long trousers OR check after walking in high grass.
If you find one those on you, you should remove them with ... special tools (like a small nipper). And after that - Burn it! Y, you can't squeeze them so you actually Need to kill them by burning them so that they die. Kind of crazy. Usually you take them in some paper and Then burn the entire paper.
So y, that's some dangerous shit right there. Forget the Bees, the Bears, the Wasps and like Jellyfishes. It's the ticks that are the real danger.
It's like 1 person/year that dies by wasps. But I've heard a lot of people that has been plagued by TBE (some probably have died by it (RIP)). So y, that's it.