Well worth the effort of a quick letter though. Addresses to write to are normally listed on CD covers. Or, if you have access to the Internet look up their website. Many bands and artists today have one. Politicians Contacting your local MP to express your view is important, even if you can't vote.
Political change occurs when new laws are passed because of pressure by constituents.
It can be a slow process, but the consequences are far reaching. Food manufacturers Consumer advice lines are normally listed on the side of the packets. Larger companies have teams of researchers following market trends. Therefore, they will be pleased to hear suggestions and comments you may have. It is reassuring to think that the use of food additives and GMOs, has been reduced and organic produce increased thanks to consumer pressure.