Earlier quoted context omitted.
Facebook could make data removable by users if they engineered their site to allow that. The problem is that they haven't, and it appears they've in fact done the opposite. We need data protection laws like this to put the onus on the service providers to make giving users control of their data a priority.
Deleting data in a complicated system is not at all a trivial task as data integrity can easily be impacted. So Facebook's excuse that they can't delete data at their scale is probably not just PR speak. For them there is no downside to keeping data besides a minority of their userbase complaining. Meanwhile the downside to deleting data is potentially huge and a mistake would be nonrecoverable. I wouldn't expect the…
From a technology standpoint it seems it's more desirable to just keep throwing storage at the problem and spend time working on ways to store and manage even more data. Data is valuable after all, so the incentive is there to accumulate and process as much of it as possible. That's exactly why we need some form of external stimulus (eg: laws) to force people to work on the problem of how can we be getting rid of data when we need to without breaking everything.