Yes and no. It only works for honest companies that comply with the spirit of the law, not just the text (the text has some failures). I worked for years buil

Yes and no. It only works for honest companies that comply with the spirit of the law, not just the text (the text has some failures). I worked for years building direct marketing software and we complied with the law best we could, and we never called DNC numbers intentionally against the spirit of the law cause it didn't make money for us (not true of others). But I can't say we never called DNC numbers cause it happens when there are gaps in file loading, or someone at a business mis-keys a phone number so we would reclassify it as active etc. Essentially (at the time, might have changed but I doubt it) a business is to register with the government, download the DNC list on a periodic basis and process their list against it. But there is a tiered set of rules. For example, if you are on the National DNC, but you had a recent transaction with a store, that store has a period of time which they can contact you regardless of the National DNC unless you opt out of their store specific list on the first call. After the defined period if you don't do any more business during that time they are to respect the National DNC again. Just an example. Sadly, a lot of companies just don't comply because they are not based in the US and cannot be touched by the US government. I've heard speculation (never seen actual proof), some of these companies use/have used the National DNC as a marketing list essentially. The list is not hashed, not encrypted, just a plain text file with numbers (at least it used to be). So it is easy to harvest for nefarious purposes.