This question already has an answer here:
If someone sets up a script that constantly runs something such as
from their cloud server or whatever that came with tons of bandwidth and so on for free, could they exhaust your own bandwidth on your server? If so, what would be the solution to stop something like this?
I suppose there does not exist solution given that in this era most web sites use things such as CAPTCHA in order to verify if someone is an actual human being or a robot..
So perhaps this in itself is evidence that there can not be a solution to bandwidth exhausting thieves and etc.