Lindsay Lohan
Everyone knows about Linsday Lohan's downfall. The child actor struggled with drug and alcohol abuse when she was a teenager and into young adulthood. She was difficult to work with, never showed up on time for filming (or at all), and was an unpleasant person to be around. She was barred from working in Hollywood, which was probably for the best. Now, she lives in Dubai.
Farrah Abraham
The 16 and Pregnant star took a huge turn for her incredibly narcissistic and abusive behavior towards anyone who disagreed with her. She was even kicked off of Teen Mom for the drama she caused on and off the set.