An excess of, or a hive-minded large mass group in one or many areas made up of individual humans acting in a "salty" manner. Many if not all of these humans make up a significant portion of the population who do not use their natural homo-sapien intelligence or intuition to an extent that is possible or practical, and instead because salty as they have been misguided to believe that their lives and/or freedoms are at stake and the only way to combat this is to act in this "Salty" manner.
An effective memetic term coined by vloggers and journalists utilized prominently after the success of the Donald Trump campain in the 2016 election and the protests by
Social Justice Warriors following the election. The Protests showed parallels and similarities to and in fact had a higher turnout than both the Black Lives Matter protests and riots in the U.S., and the butthurt brexit protesters in the U.K. who wanted to remain in the EU.
Salty meaning angry, agitated, or upset because something didn't go they way they wanted it to. Essentially a large group of"triggered" (triggered in the
social justice warrior context as opposed to the
post traumatic stress disorder context) spoiled grown up children.
So to summarize, it is a large group of salty protesters, metaphorically resembling a rich and abundant salt mine.