The firm, which also owns Instagram, violated South Korean laws prohibiting the use of information on political opinions, religious beliefs and people's sex life unless the individual provides explicit consent, Seoul's Personal Information Protection Commission said.

The nationalist leader -- a big fan of Donald Trump -- has faced backlash for his country's norm-defying EU presidency, which saw him jetting to Moscow right after taking over the six-month stint in July. Orban's frequent attacks on Brussels and fellow leaders have also left him isolated.

As polling stations open nationwide on Election Day, Democratic vice president Harris, 60, and Republican former president Trump, 78, are dead-even in the tightest and most volatile White House race of modern times.

On the Republican side, Trump has survived two assassination attempts, and frequently uses extremely violent rhetoric about immigrants.