Signing up for the national Do Not Call Registry provides limited effectiveness, as telemarketers, spam callers, and robocall companies frequently bypass the list by masking their caller ID information. This prevents consumers who file formal complaints with the Federal Trade Commission from being able to give adequate company data.
It is difficult to track violations of the national Do Not Call Registry, and for the most part, the law is not enforced. The provisions laid out by the registry exempt political campaigns from any restrictions. Additionally, nonprofit organizations and survey companies are free to call citizens on the registry. Creditors and debt collection agencies must comply with the Fair Debt Collection Practices Act, but do not face any additional restrictions from the national Do Not Call Registry.
The Federal Communications Commission offers information at FCC.gov for filing formal complaints alleging violations of the national do-not-call list.