Reddit is a good example - one of the biggest aggregators and disseminators of information for tens of millions of people, primarily in the West. People who see themselves as above-average intelligence. Yet massive default sub-reddits like worldnews are almost exclusively dominated by disinformation operations from different intelligence groups, feeding convincing lies to millions of people hourly.
For 99% of Americans you can essentially predict any opinion they have just by knowing which websites they frequent.