Fools giving away my privacy, and re: backups
The thing with privacy is that when someone is willing to give their privacy away, they are usually perfectly willing to give away other people's privacy too - people that may care about their privacy.
So when some one doesn't realise that companies change over time, as do laws, especially if that person has a poor knowledge of history, advocating anti-privacy is incredibly stupid and short-sighted.
As for back ups, I'd say they count as a relevant filing system when it comes to holding personal information, so if you write to an organisation to tell them you don't want them holding your info then make sure you mention the back ups. It will also cost them a huge amount of time and effort to get the back ups back on site and edited, making data-whoring a less profitable business model.
For example, I had some spam from one of those financial service comparison sites that I didn't want, so I asked them to remove me from their lists. Seeing as how they think spamming is acceptable, and I don't, I will never be using their service again, so they might as well remove all the personal data they hold on me too. This is how I asked them to remove my data:
"You will also delete any information from all relevant filing systems,
including file servers, database servers, email servers, live systems,
backups, off site backups, mirrors, redundant systems, copies of data in
snapshots, database exports, cached data, employee workstations,
employee email accounts, personal address books on employee
workstations, print outs, photocopies etc.. All paperwork in all
offices, data centres or storage will need to be examined to make sure
it contains none of my personal data. If I think that any of these have
been overlooked, I will be contacting the DPO."
I do care about my privacy and the privacy of others, but as there are so many fools out there willing to give away my privacy when they throw away theirs I go extra far when the law is on my side, to make businesses realise that data whoring is not acceptable. Businesses speak money only, so hit them with costs, and lots of them!