There are two examples of why people in Hong Kong protested for:
The first one started in 2003, when more than half a million people demonstrated to block the government's plan to impose stringent national security laws known as Article 23.
The next big protest was in 2012. A 15-year-old boy led the fight against having a national curriculum introduced in schools. Joshua Wong later became the poster boy for Hong Kong's most famous pro-democracy protests, the Umbrella movement.