Context: The 'OtherOS' functionality was not present in the updated PS Slim models, and the feature was subsequently removed from previous versions of the PS3 as part of the machine's firmware update version 3.21 which was released on April 1, 2010; Sony cited security concerns as the rationale. The firmware update 3.21 was mandatory for access to the PlayStation Network. The removal caused some controversy; as the update removed officially advertised features from already sold products, and gave rise to several class action lawsuits aimed at making Sony return the feature or provide compensation.

Question: What functionality did the PlayStation 3 lose in version 3.21 of its firmware update?
Answer: 'OtherOS'

Question: What reason did Sony give for taking out OtherOS?
Answer: security concerns

Question: Was firmware update 3.21 optional or mandatory if users wanted to continue accessing the PS Network?
Answer: mandatory

Question: Which PS3 model never included OtherOS?
Answer: PS Slim

Question: What legal action did some disgruntled OtherOS users take against Sony?
Answer: class action lawsuits

Question: What functionality did the PlayStation 3 lose in version 3.12 of its firmware update?
Answer: Unanswerable

Question: What reason did Sony give for taking out OtterOS?
Answer: Unanswerable

Question: Was firmware update 3.12 optional or mandatory if users wanted to continue accessing the PS Network?
Answer: Unanswerable

Question: Which PS3 model always included OtherOS?
Answer: Unanswerable

Question: What legal action did some happy OtherOS users take against Sony?
Answer: Unanswerable