Going to take the liberty of adding to this because the imprecision might cause some people to develop a poor model of how financial institutions work: you don't have a "credit account." You have a few firms which have partial views of your "credit history", sourced by reports from some firms you've previously done business with before. What a freeze does is that those firms (CRAs) who could disclose your credit history to a bank will, instead, report to the bank "That file is frozen."
How is this different from your mental model? Because credit decision is between a financial institution and a bank -- they don't have to ask anyone else's permission, including the CRA, to lend you money. They also don't have to "respect" a freeze on your file; it's purely advisory. It may deter _some_ banks from issuing you _some_ credit but it will likely not deter _all_ banks from issuing you _all_ credit products.
How does the system differentiate between someone showing up and doing something in your name vs you actually showing up and doing something negative?
[edit: spelling]
(They generally don't ask for payments till the end.)
143M accounts - lets just say 2% are rich/active enough to consider freezes. That's almost $3M over the course of say a week - for each such agency.
If enough folks write their congress critters asking for "make freeze/unfreezing free of change to everyone", maybe they will do something useful for once.
The only way someone can open a new bank account, credit card or loan in your name under the freeze is if they A) have the credit-bureau-specific PIN to lift the freeze, or B) the account was somehow opened without doing any kind of credit check.