I plan to open a site where people who are interested in X signup (fields include name, email, address and telephone number) and they appear on the site.

If companies are interested in a person and they wish to contact them, the pay a fee and then the details of the person come up for them to use.

What sort of things do I need to say in my T&C or privacy policy for the user signing up? Or can you suggest a better method of doing this (I was thinking you could ask the user to choose which details are shown, but then the address and phone fields are not mandatory so surely they wouldnt put it in if they didnt want it shown?)

Also should I be encrypting the address and phone fields in my database to comply with data protection (this is a UK based site)?

Any thoughts/suggestions will be most appreciated.