There's a difference between market research companies - those that are finding out information for either commercial or governmental or non-profit organisations - and those who ring to sell something. Unfortunately the selling companies have taken to emulating the former to trick people. Market research companies don't fall under any law except the DPA and those market research companies that ring thousands of people a year (as their statistical framework may demand they do depending on the project) may even withhold caller id. You are a cold call in the night and they wouldn't be able for calling purposes to locate your number nor would they have the admin. staff to do so, hence the initial anonymous call. The way to deal with these calls is to refuse unequivocally at the outset or the computer system will keep recycling the number. The firm calling should give a name of the caller and the name of the firm at the very beginning and, if asked, the organisation commissioning the poll/research and an admin number for the calling market research company if not the MRS (Market Research Society, a voluntary industry based organisation). You don't have to participate straight away, you can always check the caller out. Remember much information you read in the newspapers comes from these calls (all those polls saying xx% would do this that or the other). And some are private organisation polls, eg. to find out what the customer thinks about the service they got, in this case the calling company is likely to have got the name from the commissioning organisation. There are various legitimate commercial directories which these companies use, and they may also use firms which legitimately provide name/domestic telephone numbers. You can always ask where the name for calling came from - ex-directory is no guarantee that you haven't ticked a box and given out details elsewhere, ex-directory is solely the contract you have with your telephone provider which worked before the internet/ computerisation/ sharing data era. If you get no satisfactory answer, refuse to take part. Sometimes the numbers, where the survey structure demands, are area grouped, even if they are 'random digit dialling' eg computer produced. Where it becomes less happy is when these companies are allocated more information than the telephone answerer realises, eg, age range, sex, area and other variables or target profiles upon which the survey is also organised. There's nothing you can do about that, unfortunately, except inform No2Id or complain to a politician for more restrictions on data transfer. The reason for NOT asking about personal data in these surveys would be that it would hamper the commissioning company in being able to understand their buyers/people using their service (maybe older british asian people, for example, as an age ethnic group might be discriminated against etc. in using or being aware of the service). What needs to be worked upon is the security these firms use to protect the data they acquire (fortunately the range of personal data demanded has lessened under the coalition government). Remember the callers themselves are only human and unlikely to like sitting on their backsides in broken chairs staring at a computer screen at the wrong height for long periods of time, with sometimes unobtainable target calls to meet, and a general lack of appreciation by the employing m-r company for what they do give. Many realise they are seen a 'nuisance' by the person answering the call but have pressures on them outside what the telephone recepient realises to make them sound more pushy than they would in normal human communications! Many may also not realise how inundated with calls the public are.