When you enter a giveaway on Magic Bean Review, you only disclose your name and email address.
I will use random.org to generate the winner(s). In most scenarios, the post containing the winners will also boast a screenshot of the winning draw.
After the giveaway ends the spreadsheet of entrants is deleted. The winner(s) of the giveaway are then emailed asking for their mailing address. If a winner(s) fails to reply with an address within 48 hours, they may risk losing the prize, and a new winner will be drawn. In some cases, I can make exceptions if they have a legitimate excuse for not replying.
Once I have received the address, it is only used on the package. I am not responsible for any prizes that are damaged or lost in the post. I will ask for a proof of posting.
In some cases, I will not be sending the prize, rather the publisher or possibly the author. Therefore, if the prize does not arrive or is damaged through the post, I am not responsible. If the publisher or author sends the prize, they may not buy a proof of posting for the prize so if the prize is lost in the post I am not responsible.
Any email addresses or mailing addresses sent to me, or stored from my blog are not used in an inappropriate way, and once used for the appropriate way (i.e. a winner in a giveaway), are deleted.