Experian uses a variety of security systems to safeguard your information. there is actual physical security for their facilities and limited access to critical areas id strenouslly enforced.
Now as to using the Experian website, I think it is safe as far as your information is protected.But be aware that if you sign up for the "free" credit report that you read the fine print. there have been consumer complaints stating that when theyb sign up for the "free" credit report that they are then automatically enrolled in to an annual plan which automatically charges their bank account a fee each month.
In conclusion I would say that the privacy policies are geared to protect the consumers information but their online marketing practices are less then stellar.