While many have been exploited, very few have been put in a conservatorship.
Her case is basically the closest you will get to slavery. One of the few Americans with no right to counsel or voting because when someone is deemed a "vegetable" in the eyes of the law, the person is presumed to be essentially of "no mind". Only through the support and publicity generated by her fans did the FreeBritney movement grow and force the court to capitulate somewhat, since public humiliation is often the only way to prod government in such a case. I myself am a latecomer, having delved deeply only in the past month or so.
Also, her case hits personally because 8 years prior, the Montgomery County, MD government put my grandmother in a guardianship to protect the nursing home from getting sued. They further tried to flex their muscles by charging my mother with elder abuse, thinking she didn't have the will to risk trial. My mother chose a jury trial.
Medical pros can chase a buck too and nothing is worse than the drug hustlers in the field of psychiatry.
The pharmaceuticals may list the "official" purposes of drugs like antidepressants but not the other effects in which the drugs can be used for subjugation and taming. My grandmother is "diagnosed" with depression and put on Zoloft+Risperdal. Spears herself alleges that after she refused to do a dance move, the docs put her on lithium.
Ronan Farrow and Jia Talentino put the following forward, a fine piece of investigative journalism regarding the background and inside details of the matter.
How the pop star’s father and a team of lawyers seized control of her life—and have held on to it for thirteen years.www.newyorker.com
Shades of Camille Claudel's commitment to a mental facility after her father died comes to my mind. Also, Jamie Spears pulled a sort of "reverse Beethoven" as well. Ludwig's father, Johann was forcibly retired from his position and half of Johann's pay was sent directly to Ludwig for support of the family. Jamie Spears, a likewise-negligent drunkard of a dad, managed to obtain complete control over his daughter and her finance.