Jeremy Corbyn: Various tweets leading to controversies over anti-Semitism.

Ellen DeGeneres: Tweeted an insensitive photoshopped image of riding Usain Bolt

Ellen DeGeneres: Tweeted an insensitive photoshopped image of riding Usain Bolt

Elizabeth Warren: DNA test results tweet backfired.

Elizabeth Warren: DNA test results tweet backfired.

Jeremy Corbyn: Various tweets leading to controversies over anti-Semitism.

Jeremy Corbyn: Various tweets leading to controversies over anti-Semitism.

Ted Cruz: Liked a pornographic tweet, causing embarrassment.

Ted Cruz: Liked a pornographic tweet, causing embarrassment.

Sarah Palin: Tweeted about the "Lamestream Media".

Sarah Palin: Tweeted about the "Lamestream Media".