How can I hide a product category to non-logged in users

Hi there!

I'm wondering if you can help me with some code... I'm trying to make one product category in MarketPress that is only available / visible to logged in users.

I've called the product category 'Member Products' with slug 'member-products' and I want to find a way that is does not appear anywhere in the site to visitors (widget, store page etc.)

I've been playing with the is_user_logged_in request for a while with no luck... help would be much appreciated!