Comment by wavemode

A key distinction is that people need employment. People don't need to fill out surveys. That's why there are many things companies aren't allowed to require of their employees, that they are allowed to require of other parties.

So while, in many jurisdictions, it's fine for companies to sell data collected on their employees, and it could be argued that those employees consented to this data sharing by working there, one could also easily argue for an employee protection law that prevents companies from requiring their employees to consent to this.