Heartland

Basically, I received a letter yesterday where the content of it was very visible through the "window".

Does anyone know where I stand on this re: Data Protection?

I have not yet opened it, but two family members noticed it before I did.

Sue Em..

so what was it??? PORN???

You could try complaining to the company who sent you the correspondence, but they could probably reasonably argue that by sending a letter addressed to you, at your own address, they haven't intentionally disclosed information to an unauthorised third party

If sensitive personal information (e.g. financial, medical) was clearly visible without even opening the correspondence, you may have more of an argument, but they probably would be unwilling to pay compensation or a goodwill payment unless you can show that there have been any repercussions from other people having access to this information.