In summary, they are treated as second class citizens. Racism against them often have racial and religious elements. The Malaysian Chinese are often as associated with the former Malayan Communist Party, even to this day. There was a pogrom against the Malaysian Chinese in 1969 called the "May 13" incident.
Malay supremacists can say racist things about the Chinese and even threaten violence, but gets no punishment. Malay hooligans can even vandalize Chinese businesses and get light sentences. Any Chinese who responds openly will often get arrested and sometimes jailed for "disturbing the peace". If a Chinese is accused, even falsely of insulting the Malays or Islam, it often escalates into a national controversy.
These days the tensions have somewhat simmered down. Thanks to progressive Malays like Anwar Ibrahim who had been trying to stop the racism. But they are still a minority, and decades of racism cannot be changed overnight. There is still plenty of Malay racism against the Chinese that continues to bubble under the surface.
Not to forget about them. The Malaysian Indians have also been treated just as badly. They are also second class citizens, and have also seen their own share of racism and pogroms.
All this is a legacy of the British. They split up the communities on Malaya by race to fight the Communist insurgency. The Chinese in particular have been specifically targeted. Then when the British left, they left behind a nation divided by race and religion.
