Exactly. They can use it to boost the opinions that they favor. The feedback loop of "I talked about opinion X and got tons of love" and "I talked about opinion Y and everyone got mad / ignored me" is very powerful, especially on young people.
* "X seems to be a pretty big deal because I keep hearing a lot of people upset about it"
* "I haven't seen anything about X. It must not be that big of a deal."
All social media seems to be moving toward individualized echo chambers, but it's another level when it's an individualized black box controlled by foreign interests.
It's not hard to understand, it's literally because it's controlled by China.