Why is Hong Kong's China extradition plan so controversial?

Hong Kong witnessed its largest protest since the city's 1997 handover to China on Sunday as hundreds of thousands came out to oppose plans to allow extraditions to the mainland.The city's government is pushing a bill through the legislature that would allow extraditions to any jurisdiction with which it does not already have a treaty -- including mainland China.Hong Kong leader Carrie Lam says safeguards are in place to protect the city's free speech, and to ensure political cases will not be a