I came across a sentence on the language-learning site Duolingo that said
Много людей в Европе и Америке знает о Петербурге.
знает used instead of
One suggestion in the comments was that a singular verb is used when a group acts as one entity, but in this case it seems to me as though each individual knows about St. Petersburg.
Can someone explain the usage of singular verbs for multiple things/people?