I believe the usual term is a "bill of attainder". The US has a long-standing constitutional prohibition on doing this, though apparently Australia does not.
I think you'll find the US often has lists of corporations and people overseas that US corporations and persons are not allowed to work with/for. The US also has provisions designating companies as of national security importance and other areas.
This draft law allows the relevant government minister (in this case the Treasurer) to designate certain corporations as subject to this law. The corporations have access to the courts to challenge the designation and requirements of "natural justice" have been applied to ministerial actions by the courts.
Facebook and Google aren’t hard-coded into the law. The law applies to “designated digital platform corporations.” The executive government can add or remove companies from the list at “runtime” (without passing a new bill), but the explanatory memorandum linked above says that initially only Facebook and Google will be designated.
