Obviously they're not "literally" picking the next president, however they have full control on what opinions you see first, and they have utilized that ability to tilt many (yes, very many) people's opinions (especially those whose understanding of even general politics is superficial) towards a specific candidate.

Under that logic we need to heavily regulate cereal boxes and milk cartons because many of us see that first thing every morning.

My philosophy is to always be suspicious of those grabbing at the keys to power - they are up to no good.