Data mashing is a term used for taking and combining data from different sources to create new and often innovative services. This is most commonly done with published structured data made available on the world wide web via application programming interfaces, using data and services from providers such as Google, Yahoo and Amazon. Data mashing is the process, the mashup is the product.
In the United Kingdom, all forms of processing personal data are regulated by the Data Protection Act 1998. Although the Act does not refer specifically to data mashing or mashup, its provisions will apply where a website operator in the UK takes legitimate public sources of information about individuals and then publishes a combined version of that information on the internet. In particular the first principle requiring the processing to be fair and lawful will apply.