How do I prevent my clients from seeing my full portfolio?

I’ve got the WPMU Dashboard installed.

I also have a developer membership, which allows me to use WPMU on multiple sites. This is an awesome resource to have available when I’m pitching new business.

As of right now, any client can simply log on through the dashboard to post here or view the last 4 digits of my credit card number. If I remove the dashboard, they get a nag asking them to add it for updates.

What I need is a way to cut a client off from seeing all of my information (including other clients!). What am I missing? This must be my oversight. It seems too big to be yours.