There is no CabalTINC is a Usenet abbreviation for There Is No Cabal. See backbone cabal usenet cabal and news.admin.net-abuse.usenet, but note that this abbreviation did not enter use until long after the dispersal of the backbone cabal.
The abbreviation TINC is used humourously to indicate that people should lighten up and not see a conspiracy around every corner.
As Usenet has few technologically or legally enforced hierarchies, just about the only ones which formed were social hierarchies. People exerted power through force of will (aka psychological terrorism via flames), garnering authority and respect by contributing to the community (e.g. being a maintainer of a FAQ), or through sheer persistence, spending more time and writing more posts than anyone else (see Kibo, etc.). See also the Usenet cancel wars.
Thus groups of people with authority and power did so with what in a traditional society would be considered extralegal means -- they were, in some sense, cabals. In another sense, they were not cabals, since their power was little more than social authority.