And then they will also use that information to help other companies poach your employees, at best. At worst, the data will be purchased for some sales team to identify and target your company to sign some wildly overpriced long term sales contract. They will know employee behavior and who the key prospects are in your organization.
It has happened before.
Even I was shocked how tens of thousands of companies handed over mind blowingly valuable customer data to Facebook. They aggressively promoted their Facebook Page to their customer base: please like us on Facebook!
What did Facebook do? They took that data and sold it to competitors as ad inventory. I never saw a single company owner complain. Companies spent millions of dollars and years of effort building up a customer base, and just handed it right over to Facebook.
To put it in more blunt terms, Facebook stole companies assets through social engineering. I saw friends turn around and build profitable, multi-million dollar businesses through this single data usurpation channel.
Will companies get more savvy about locking down their data? I'm not counting on it.