This is something we discussed many times internally leading up to the release. Mechanisms were already in place to restrict the files if we decided to go that route. The long and short of it, though, is that:
- The people registering for the forums were folks that were already pledged, either through Kickstarter or PayPal (so if you don't recognize a name, that might be the case)
- We wanted the files to be easily accessible to everyone who should have access to them.
- We also didn't want people with no other local backers to be unable to take advantage of the playtest -- so if you want to test it out with your friends, please do.
In the end, we wanted to avoid keeping backers out more than we wanted to avoid letting their friends in. There might be a couple of freeloaders in the short term, but you'll still get the models before they do, and chances are they're here because you (or someone like you) told them about it. I hope knowing the rationale behind the decision helps it rest easier with you.