The problem for these companies is that hoarding and monetising data _is_ their business model. If they can't do that anymore, they are going to struggle in a serious way.
This is what happened to the banking industry after the 2008 financial crisis.
* The FTC actually does something about this in a way that companies in a similar manner are also affected (directly or indirectly) * These companies don't find a way to get around the issues.
I'm not convinced anything will significantly damage tech companies whose primary profit driver is their users' data anyway. The general public has been using them for years now and despite any outrage, it's become too integrated in society for people to suddenly stop (unless someone comes up with a better alternative).