It's a precomputed hash that let's you know if an item is (kinda) in a set or not. Fast and uses up very little space.
See: https://en.wikipedia.org/wiki/Bloom_filter
What you are talking about with graphics is: https://en.wikipedia.org/wiki/Bloom_(shader_effect)
Haha no surprise there. I said a few weeks ago in a comment this is what will happen and got massively down voted. Because if he admitted that he knew of the crimes, then he is 1. guilty for doing nothing about it despite being in power or adjacent to powerful people, or 2. is a pedo himself. So all he can do is say he knew nothing in order to save his own ass.