There is an explanation here:

Basically the terms of service say that anything you type or record using the impervious browser becomes the intellectual property of the impervious company and they are allowed "to use your Contributions in any manner contemplated by the [company]." Including by selling your information:

"you automatically grant...to us an unrestricted, unlimited...worldwide right...to host, use, copy, reproduce, disclose, sell...and distribute [your] Contributions (including, without limitation, your image and voice) for any purpose."

When this was pointed out to them in the thread above, they dismissed it by saying it's just legal language that doesn't mean anything: "this is literally nothing. Love you all."

Some people are mad about that. If it's truly nothing, why not change it? They refuse to change it so far, and that gives the impression that maybe it's not nothing after all.