The powerful algorithms that fuel social media platforms are feeding users days-old and sometimes completely fake content about the recent unrest in L. A., contributing to a sense of nonstop crisis that doesn’t exist beyond a small part of the sprawling city.

A young man declaring his intention to "peacefully protest", before throwing a Molotov cocktail.

Unrest in Los Angeles follows a recent pattern: Protests that break out remain mostly peaceful during the day, but at night agitators engage in fiery clashes with police.

The masks and other gear worn by some protestors, and trademark riot techniques such as breaking apart curbs to lob concrete at police vehicles, have raised questions about whether experienced agitators are involved.