Giving away your personal information

This morning I received an email from TransUnion, informing me that someone has been accessing my personal details on their website. TransUnion refuse to tell me who this was.<br> <br> I am not opening new accounts or applying for credit, and haven't done so for the past year at least, so I can only assume that someone is engaged in identity theft.<br> <br> It was my understanding that anyone wanting to run a credit enquiry needed my permission. TransUnion appear to have facilitated this enquiry without receiving the proper permission. I certainly haven't given anyone permission to run an enquiry on me this year. <br>