I'm not sure whether there'd be legal liability; that would probably depend on whether the third-party was aware of the scheme, and how often they 'enabled' it.

I'm not sure whether there'd be legal liability; that would probably depend on whether the third-party was aware of the scheme, and how often they 'enabled' it. I doubt that the SEC would be found to be an accessory the first time this happened (unless they'd been specifically warned), but if this happened frequently, I think they'd likely be found guilty by way of 'reckless or wanton negligence'. They might even be subjects of civil actions by victims of these blackmail schemes at a later date (if the circumstances were right).