Comment by flir
In the UK, the Computer Misuse Act applies if:
* There is knowledge that the intended access was unauthorised
* There is an intention to secure access to any program or data held in a computer
I imagine US law has similar definitions of unauthorized access?
`robots.txt` is the universal standard for defining what is unauthorised access for bots. No programmer could argue they aren't aware of this, and ignoring it, for me personally, is enough to show knowledge that the intended access was unauthorised. Is that enough for a court? Not a goddamn clue. Maybe we need to find out.
robots.txt isn't a standard. It is a suggestion, and not legally binding AFAIK. In US law at least a bot scraping a site doesn't involve a human being and therefore the TOS do not constitute a contract. According to the Robotstxt organization itself: “There is no law stating that /robots.txt must be obeyed, nor does it constitute a binding contract between site owner and user, but having a /robots.txt can be relevant in legal cases.”
The last part basically means the robots.txt file can be circumstantial evidence of intent, but there needs to be other factors at the heart of the case.