They didn’t repeat the same 3 ads every few minutes on high ad videos (No It, I will not take it >:c)
Moderated and removed obvious scam ads
Remove ads that are disgusting or clearly inappropriate (I have seen some stuff that could be categorized as porn in YouTube ads and no I do not allow them to feed me ads based on my interests)
If ads were still not being actively used to spread malware/viruses (not sure if this happens on YouTube at all but I would rather be safe then sorry)
Isn’t that the xscreensaver logo