Scraping websites that does not have a Terms of Service [on hold]

This question is more related to law than technology, but it's a legit question that can impact my project.

As far as I know, you can't scrape somebody else website without obtaining their prior written permission, or in disregard of their Terms of Service (ToS).

But what should I do when I need to scrape a amateur site that doesn't have a ToS and the owner is anonymous (I didn't found any information on WhoIs services about this specific site)?