Hi Mike, just to be clear on what Thomas is suggesting, as I think he might be getting mixed up between noindex and robots.txt.

If you simply add noindex,nofollow to a bunch of pages, this could still get you in trouble. Noindex doesn't mean DO NOT CRAWL, it means DO NOT INDEX. There's a big difference.

If something has noindex, Google can still crawl that content but they won't put it in the search results.

The only way to completely make sure that Google won't crawl content is by blocking it in robots.txt or in your case putting it behind a username and password.

So to answer your question, yes it's fine as long as it's behind a login, Google can't punish you for it since they can't see it.

I hope this helps,

Craig