I don't believe that 99% of Facebook users would tick a box that said 'Please record every webpage I visit and store it for your own future use. I do not want access to, nor the right to remove, this data.' Voluntary or not, there's a right to at least see the data that anyone holds on you. Note that you don't have the right to remove data.
This is EXACTLY why data protection laws are there. At the time they were enacted it was largely credit reference agencies, public bodies and direct marketing businesses which were in the spotlight. Had they been written today they would be aimed firmly at Facebook, Google and Apple.