A proposed extradition law in Hong Kong has set off alarm bells not only within the former British colony, with the Legislative Council (Legco) witnessing violent clashes between pro-government and pro-democracy lawmakers opposed to the bill, but also from the international community.

Why? The territory remains one of Asia’s pre-eminent centres for multinational regional headquarters and its airport is one of Asia’s busiest international aviation hubs. Critics fear the law would allow Beijing to nab anyone it likes who sets foot in the territory — from a normal resident to the chief executive of a multinational in transit — and whisk them off to mainland China on trumped up charges.

Here is how the proposed law would work and why it is drawing some of the biggest protests Hong Kong has seen in years.