How could a stranger edit my form?

Hi! 

I got a message from a customer that my form was odd.

When I checked it, it was back to scratch and my form from last year was showing! 

I checked the revision story, and a "guest" had made 43 changes! 

How can this happen, and how do I prevent it?

That is indeed odd. The guest account usually shows up when you are not logged in to your account and you are creating or editing a form. 

If you are opening the form builder in multiple tabs in your browser, that may also caused some problems in makings changes to your form, we advise that you closed other tabs that has the form builder opened or avoid editing multiple forms at the same time.

You can also check your "History" section in your account settings, you can check if there's an unfamiliar IP address or form modifications at that time.

We could further investigate and escalate this to our developers. But I believe this is something related to your session being timed out and logged out while editing the form.

Apologies for the inconvenience.