BuddyPress.org

I would do this by going into /member-themes/buddypress-member/blogs/create.php and doing…

<?php if ( bp_blog_signup_enabled() ) : ?>

<?php

global $bp;

$blogs = bp_blogs_get_blogs_for_user($bp->loggedin_user->id);

if ($blogs['count'] != 9)

{

bp_show_blog_signup_form();

}

else

{

?>

<div id="message" class="info">

<?php _e( 'Limit nine blogs per member. If you would like another, please contact an Admin for assistance.', 'buddypress' ); ?>



</div>

<?php

}

?>



<?php else: ?>



<div id="message" class="info">

<?php _e( 'Blog registration is currently disabled', 'buddypress' ); ?>



</div>



<?php endif; ?>

Just remember not to overwrite the member theme if you do a BuddyPress update.