Administrator only?

Hi echoleaf.

I asked myself this question before releasing the plugin. I concluded that changing the author’s url has an impact on SEO, so it shouldn’t be done frequently. So only users with the “edit_users” capability should be able to do that.
But, of course I thought there would be some people who want to allow their users to edit the url, so, you can add the following in your theme’s functions.php file:

add_filter( 'sf_auc_user_can_edit_user_slug', 'sf_auc_allow_non_admins' );

function sf_auc_allow_non_admins( $allowed ) {
	return current_user_can( 'edit_posts' );
}

This code allows Contributors (and up) to edit their own url. If you want to allow Subscribers, replace ‘edit_posts’ with ‘read’. Reference for the users capabilities.

Cheers.