Todor Zhivkov to 1988, Bulgaria won an unprecedented 153 Olympic medals and numerous European and world competitions in sports as diverse as volleyball, rhythmic gymnastics and wrestling. Dissent was punished under Zhivkov's rule. The CSS was a feared tool of control, and overt opposition largely stayed underground until the late 1980s. In 1978, the Bulgarian dissident Georgi Markov was assassinated in London by an agent who stabbed him with an umbrella tip which implanted a very small ricin ball. According to former KGB general Oleg Kalugin, this was requested by Zhivkov and either performed by the KGB or it assisted the CSS;
Ricin James Mattis, and the other to Chief of Naval Operations, Admiral John Richardson. Ricin has often been used as a plot device, such as in the television series "Breaking Bad" (Season 2, Season 4 and Season 5). Ricin pellets were also used as the murder weapon in the "NCIS Season 7 Episode 21 – Obsession" The popularity of "Breaking Bad" inspired several real-life criminal cases involving ricin or similar substances. Kuntal Patel from London attempted to poison her "controlling and selfish" mother with abrin after the latter interfered with her marriage plans. Daniel Milzman, a 19-year-old former Georgetown University student,