yes its against tos if they don't have any written content and placing them just near videos agaording to rules . But even i havee seen many sites . May be google is just watching and one day we will find bad news that more than 1k account suspendedon this .
example i have my site with copyright with youtube is that ok? anyway thanks for your suggest for wrote to google about my weird earning last day , google already replied and they said thank you for my attention about reporting that causes.