Speaking of good ideas... the law is on your side if you protect your ideas or inventions.
Intellectual property rights can be protected properly - there's lots of information about this on the Legal Choices Ideas page.
However even if you have got intellectual property rights you can still be the target of scams or misleading advertising.
These could include being contacted by companies advertising services to help you renew your rights, to list you in a publication, or to help you have a trade mark overseas.
However only four organisations can provide legal protection for UK trade marks, patents and designs (which are the Intellectual Property Office, the European Patent Office, the Office for Harmonization in the Internal Market, and the World Intellectual Property Organisation.)
In December 2013 the Advertising Standards Authority upheld a complaint about an invoice sent by a company advertising services in this area, but that had no affiliation to the above organisations. The details of the decision are on the Advertising Standards Agency's website.
The advice is simple - don't pay a penny if you own intellectual property rights and are contacted out the blue by any company offering services like these until you have done your homework.
If you use a lawyer like a patent or trade mark attorney or a solicitor you can contact them for advice. See the Legal Choices page on patent and trade mark attorneys for more details.