[rahimnathwani]

There was a Black Mirror episode which included that. It started off simple: a mother subtracting a scary dog from the view of her young daughter.

[thih9]

What could possibly go wrong?

It sounds interesting on a psychological/developmental level too, children are routinely taught to ignore certain thoughts, concepts or emotions. Looks like technology could offer increased level of granularity and control. Scary times.

[brokenmachine]

Aah, the old Joo Janta 200 Super-Chromatic Peril Sensitive Sunglasses from Hitchhikers Guide.