You trade control for participation. The more control you give to your members, the more they participate. Imagine a line, at one end is giving members no control, at the other end is giving members complete control of your community.
Too many organisations begin at no control and demand reasons to give members any control. They might gradually add in comments, light profile customization and allow some moderators. This severly limits participation.
This 'no control' default is wrong. You should begin by assuming you should give members total control and work backwards. Every control you take away should have a good reason.
For example, you can’t give people full control. You can’t give supporters the ftp details and access to edit your source code. That’s sheer madness. One mischievous tyrant can ruin it for everyone. Nor can you hand everyone full admin powers. Members would probably delete members they didn’t like. Soon, there would be no members left.
But can you let members say whatever they want? Can you let them create forums on their own? Can you let them decide what content shows on the front page? Can you let them vote to ban members? Can you let them change some design of the website.
If you can’t think of a valid community-threatening reason to say no, then say yes. There are a thousand things you can let members do if you think about it. Sadly, most organizations don’t think about it. They begin thinking about control at the wrong end of the line.