I can change the subject name at will, again and again.
I can modify and erase, again and again, almost all of the message body, except I cannot left it empty.
That’s why in these cases the Moderator can simply move this to where it belongs. I have no idea why that hasn’t been done already. The solution is NOT to allow the OP to just delete a thread which contains others people’s posts.
Here is above, another alternative solution (while waiting a Moderator) that an Opening Poster can do on its own Opening post.
It is possible to left almost everything blank, except for 1 single character (a dot is enough) in this two:
No subject was filled in.
The message body was left empty.
So if someone is starting a new thread in the wrong forum, just let him know that he have just to start a new one in the good forum and just copy the message body from his older one.
Then, once it is done he can erase everything and left a single dot “.” in both subject and message body section.
The OP is not powerless about is own post and starting thread.
He can also left a message like this: “To mod: Erase this thread, please.”
All the others replies can be easily erase by each author.