Neighbor's tree - Security and dirt. Who is responsible?

Pragmatic approach is the best. If he's not at home, then cut everything back to the border. Yes, I know, you then have the work with it, but better that than endless disputes.
By the way, this is not punishable!

Hahaha........You are really great. Bam, dear community, here is the solution!
So it only avoids "endless disputes" as long as you do it in the neighbor's absence? In which yellowed mediation brochure was that to be found? :D Wonderful........
Punishability is only a very small part of such a topic.

if you saw something being cut down now, I as a neighbor would have seen a nest there that is no longer there.

This will be expensive.

That will be expensive.

....but guaranteed no argument :D :D :D

That is not a criminal offense, by the way!

I have to correct that: it is a criminal offense. The trees are the neighbor's property. No one has the right to cut them, otherwise it is property damage.
However: I could probably live with the "penalty," but not with hostile neighbors. You have then started a war at the chain-link fence yourself.

I also have to honestly represent the other side for once: when I have to look at these plastic fences, I just become stubborn.

Then there is also the chicken-and-egg question: is he acting so stubborn because you don’t seek any neighborly contact anyway, are distant and have built these partitions?

Did you even try to establish contact before your first official action? Introduced yourselves, invited him, and chatted?

Which federal state are we actually talking about? In S-H, for example, to my knowledge such a tree is allowed to grow as long as nobody objects. And for 20 years, no one objected.

Have you ever questioned yourselves: The pictures don’t look that dangerous, of course that can be deceiving? It surely has nothing to do with the shadow casting? Pine cones are not dirt… even if I don’t like such trees at all.

I’m just imagining these were my trees. I have lived here for 30 years, planted them when I moved in, now there are many new neighbors. A neighbor comes along, has lived here for 2 weeks, and immediately makes demands that the trees have to go or at least be cut by half. His child is in danger!

I would also reject that. Because he just wants more sun and I think he’s mocking me. He obviously knew before that the trees were there.

He comes and asks if the dead branches can be removed, he would also like to help. I would consider that.

But there are also simply blockheads who just don’t care about anything and don’t care at all :D