Having been the victim of a VERY badly behaved scraper, I'm willing to listen to this. When that "attack" was going on, we talked about that very thing, if the scraper would only identify himself. (we were able to identify the actual culprit, and circumstantial evidence suggested they were going after our complete price list for a client)

The cost of the bad scraper was pretty significant. They were hitting us as hard as they could, through TOR nodes and various cloud providers. But the bot was badly written, so it never completed its scan. It got into infinite loops, and triggered a whole lot of exceptions. It caused enough of a performance drain that it affected usability for all our customers.

We couldn't block them by IP address because (a) it was just whack-a-mole, and (b) once they started coming in through the cloud, the requests could have been from legit customers. We eventually found some patterns in the bot's behavior that allowed us to identify its requests and block it. But I'd have been willing to set up a feed for them to get the data without the collateral damage.