Trolling
Trolling is the bane of all online discourse. Disingenuous trolls who spread misinformation for lulz have mixed with foreign agents being paid to sew political discord, and repugnant randos who actually believe in their hateful messages, to become the dominant force in many online conversation spaces. They are shaping policy, influencing the outcomes of elections, and making the internet bad.
Not to mention their outrageous rates for bridge crossings.