To the best of my knowledge, the laws aren't so much about making information disappear, it's about preventing companies from profiting from information that customers don't want being used. That's why the punishments involve fines to gross income.

It's certainly possible to purge personal information from Flyertalk (IB has already admitted as such), so your impossibility defense seems irrelevant, like saying that anti-smoking laws are not enforceable because air pollution is ubiquitous.

I apologize for my difficulty in explaining the relevant technical concepts to you. I have 45 years of computer experience, including being the first non-scientist with regular access to the internet (the IP address was 2 digits when I first got regular access), so I sometimes don't synthesize well enough. Let me try one more time. You misunderstood what IB said. What he meant was (with apologies to IB who is free to correct me) "I can search and delete every post by Hailstorm and I can search and delete every quote of every post by Hailstorm and, if required, I can search the word "Hailstorm" and delete it from every post. However, there are POTENTIALLY serious consequences to stability of the website if I really do that." What he didn't say in his comments, but which I also think is true, is the following:
A. If I do that today, and the system crashes big time tonight, and if I restore the system as of midnight last night, all my work will be wasted because you will be back again; B. You are on every backup we ever did, so if anyone with legal subpoena power wants to find you, you won't really be forgotten - they can still get every post and every quote virtually forever. C. We can't delete you from the Wayback machine or from Google or Bing or Yahoo or anyone else who crawled and copied your posts, so even ordinary people can probably find you for a long time. D. Assuming we have redundant colo facilities, you won't be forgotten by them (at least until the current backups cycle through). E. The contracts between IB and its advertisers won't require them to delete you from their records, so you might still get solicitations, etc. (a profit making venture)l. F. Every member (and guest) who has ever copied one of your posts will have those copies forever and they may repost a bunch of your stuff the day after I delete it, so you will STILL appear on FT. And that isn't the whole list.

I've nothing new to add, except that, if you think that technology renders laws obsolete, then we really have gone from technology working for us to us working for technology.

I would agree with you. And that is the point we have reached. It USED to be that a salesperson could say "Gee, that one is dented, I will charge you 1/2 price." Now they can't do that unless the computer says that they can. And one of the reasons I think GDPR is so ridiculous is because I gave a speech almost 20 years ago in which I pointed out that our conceptions of privacy were outmoded because of technology. Does technology give us benefits? Sure, lots of them. Is is possible that someday technology will give us the benefit of privacy? It is certainly possible. But right now, based on current technology, is the idea that a GDPR citizen can limit their data to the GDPR region or GDPR compliant systems reasonable? No.