Let us say - for the sake of this discussion - that you, Jody Paterson, have decided to apply for a job as an entry level position at one of the big corporations. Let us also say that you are fully qualified to do the job and the local office has approved you. The local office passes along your particulars to the corporate level for routine final approval, but corporate turns you down. Why?
You never find out, but the truth is that corporate ran an automated background check of your online activity and found out that your views did not match theirs. Had you been writing anonymously Big Brother would not have known what you think.