It's not the idiom, it's poor structure; the object of the clause is ambiguous and could mean "responded to my writing" or "responsed to Mark Zuckerberg". E.g.

It's not the idiom, it's poor structure; the object of the clause is ambiguous and could mean "responded to my writing" or "responsed to Mark Zuckerberg". E.g. "While I wrote" or "After I wrote" would remove the implication of causation that "When" has. But really it should just say "The street responded by savaging..." with no authorial preening. That being said, it's a weird thing to get hung up on.