Voldemort

[…] Oscar has been called the Voldemort of Fleet Street by both friends and enemies. He was apparently ruthless in all his business dealings.'

Source: wiktionary

If you asked me to identify a Voldemort in the myth of “social media,” it would be these people, and not guys like Gary Vaynerchuk.

Source: wiktionary

Fructose is the Voldemort of the metabolic syndrome pandemic: stealthy, ever-present, and bad for the common good.

Source: wiktionary

Rather than just extracting one taboo word and replacing it with another, online Voldemorts spread and mutate into dozens, even hundreds, of potential synonyms. […] (In perhaps the most ironic example of Voldemorting, I once tweeted the word Voldemort itself and my tweet was liked by two separate parody Voldemort accounts, presumably hoping to juice their follower count through a little social media Dark Arts.)

Source: wiktionary