In a past life, we were consulting with a startup that offered a subscription data service. They were very sensitive about scrapers, especially on the time limited try-before-you-buy accounts, which competitors were abusing.

At their request, we built a method to flag accounts for data poisoning. Once flagged, those accounts would start getting plausible-ish looking garbage data.

It was pretty effective. One competitor went offline for a few days about a week after that started, and had a more limited offering when they came back up.