I hope unionizing against these tech giants becomes fashionable. I worked at Adobe as a contractor and one of the recruiters for the contractor had called me and told me not to discuss my pay because I was being paid very well for the job (I wasn't and in fact was underpaid but I took the job to build a resume). I immediately asked my coworkers what they made and told them what I was getting. I also asked the recruiter to send that in writing. I got a call the next day from his manager saying to ignore and disregard what he said.

While they squashed the issue immediately, I suspect this practice is common and bullying people about sharing their wages in this industry is normal.