Has to do with reporter case demanding publication of grand jury materials associated with the Mueller dossier …
https://www.rcfp.org/reporters-committee-for-freedom-of-the-press-asks-court-to-authorize-release-of-grand-jury-materials-included-in-mueller-report/
Congress gave the internet provider/censors immunity, see 47 USC 230
https://www.law.cornell.edu/uscode/text/47/230
They are expressly exempt from liability, with nothing to do with "public square vs. publisher" distinction. Congress has made interactive computer services immune from liability, period. This is a Congressional policy choice. Congress also gave the interactive computer services the power to deny access.
The presence of near monopoly in the field of interactive computer services and "news" has resulted in the opposite of "free" speech. This is by design. Congress and the press are truly enemies of freedom.