The issue here is to prevent people from getting your informations with ill intent, therefore we suggest that you don't advertize your social security number, any official number (ID, passport) and obviously your bank accounts details.
Obviously, this means you shouldn't have any copy of such documents in your portfolio either. If a company, an employment agency or a temporary work company needs those informations (which they probably will at some point), you should send it to them in a personnal or confidential way. Last but not least, it is advized not to show you birth date and your address simultaneously. That's why DoYouBuzz displays your age and your home town instead of the full information.
Having a letter of reference is a good thing obviously, but if you intend to publish it on your CV, you need the approval of it's author. You should also make sure, on a public version, to delete any personnal information , such as his address, phone number or email.
Regarding the portfolio, you need to have the legal rights on the document you want to publish. We see from time to time people publishing confidential documents, more often than not documents that really belong to your company. The reason is that your company is very often the sole proprietary of what you wrote as an employee for them. The only way to deal, legally, with this is to ask your company for an authorization to publish.
Overall, you are responible for everything you publish on your CV, therefore you need to respect authorship and intellectual property lews.