The do not call list does work, but it's notas good as it used to be. The thing that changed was when bulk-purchase of international telephone calls came down to be much less per minute that the cost of a person to make the calls. Then overseas call centres could compete with UK-based call centres for the sales business. International enforcement of DNC is justabout impossible. UK-based callcentres will lose their phone lines if there are enough complaints made aboutthem, but internationally that won't work. Any system like this needs maintenance to keep up with changes in technology as well as market changes, and while DNC was initially good, its utility is decaying, but is not yet zero.