This was my experience as well. (Well I didn't come from an HFT company but on arriving at Google and then seeing some "dubious" things get diverted to ephemera

This was my experience as well. (Well I didn't come from an HFT company but on arriving at Google and then seeing some "dubious" things get diverted to ephemeral media, because possibile suits, was a thing.) What I found interesting was the rationalization that "people would just cherry pick data and use it against us." Which belied the idea that if you saved all of it, you would be able to reconstruct it. Also the storing of live traffic not to "look at" but to have a model of live traffic to test changes against. I once asked "why not create a statistical model of the traffic and use that?" and was responded "#1, people wouldn't believe you if you said this was 'just like actual traffic', and #2 we get live traffic for free with no engineering effort so its a win to use it instead." They weren't wrong but they didn't really prioritize privacy or safety either.