Section 230 isn't absolute, there are several specific exceptions. One example is the FOSTA law from 2017 which explicitly overrides Section 230.
https://www.congress.gov/bill/115th-congress/house-bill/1865
> The bill amends the Communications Act of 1934 to declare that section 230 does not limit: (1) a federal civil claim for conduct that constitutes sex trafficking, (2) a federal criminal charge for conduct that constitutes sex trafficking, or (3) a state criminal charge for conduct that promotes or facilitates prostitution in violation of this bill.
There are some other examples I'm not thinking of off the top of my head, but on a note directed more towards the general discussion, I'd point out that creating laws to limit the scope of Section 230 is illustrative of the kind of freedoms it affords site operators in the general case.