It can be forked by anyone, but what is already out there will always be there.

And how does this hurt all of us who use it for open source projects?

The network effect is real. You can have the best, most awesomely-designed social media platform ever and it will be useless if you are the only person on it.

You can try to convince all your contacts to switch away from whatever app is causing the most evil today, but you also have to convince all of your contacts’ contacts and all of theirs as well.

If your router/firewall is configured to let these broadcasts through you have a problem. If it is working correctly and you have an attacker on your lan? You have already lost.