Reported by; rnjonjo & clicks, here;
http://forums.b2evolution.net//viewtopic.php?p=44502#44502

At the moment, if you give a user permission to make posts, they also get permissions to edit posts. I know b2evo clearly states this. But really post and edit permissions should be seperate.

A use case scenario would be;
I set up a multiblog enviroment with b2evo, a new user registers, he gets a blog, but with b2evo without this feature, he also gets permission to edit everyone elses posts!

So yeh, this feature should be in b2evo by default.

We don't mind if it comes in future releases of b2evo (e.g. the 2.x series), as EdB has volunteered himself to do it for the 1.8.2 release ;)

So yeh...

Update:
It is added into the core for 2.0, and a plugin is available for the 1.8 (maybe 1.9) releases here;
http://forums.b2evolution.net//viewtopic.php?t=10236