What counts as customization? I might agree that most people don't care to change font sizes or colors or even themes but they might want to be able to tell Goo

What counts as customization? I might agree that most people don't care to change font sizes or colors or even themes but they might want to be able to tell Google to never return results from a particular site. Is hiding results from a site customization? Is it the sort of customization that would overwhelm a user if they saw it as an option?