Consult a laywer before believing anything I say, to be safe. I am not a lawyer.
This will depend on the value of what is taken, among other things. Such behavior falls under "trespass to chattles" which is traditional law about trespassing, and is applied to internet cases as well. if you caused the bot to traspass, and it qualifies as trespass to chattles, you can get into trouble.
If some techie says "if they didn't bann it in robots.txt then it's ok" ignore that... it's nonsense. Society is not technical, and the law doesn't yet require publishers to be technically competent. The laws are still the same old trespass laws, re-argued in modern court.
A university I know spent $30,000 over 3 days on security consultants in response to a network breech. Find it, stop it, tell us how it got in, close the hole, help use make a case to prosecute. All the kid did was access via a stolen password, and start a job that consumed so many server resources the univeristy network came to a crawl. In the end the Univeristy calculated costs into the mega millions... lost research time, staff time, down time, etc etc etc... and used that as leverage in their legal proceedings.