We already know that there are cameras all around us. You are hardly ever private when you use social networking sites. You know about how your criminal past may easily come back to haunt you. But did you know that dropping a seemingly harmless slip of paper could also open a door to destroy your privacy?

I was in Starbucks the other night, thinking about what I wanted to order when I noticed what appeared to be a small business card on the ground under a table.

I try to pick up such things so that I can return it to its original owner if it turns out that it is of some valuable. Rather, it turned out to be a card handed out by a company that specializes in taking pictures of people at nice looking locations — this one in particular happened to be the ice pond at Bryant Park.

The card gave instructions on how I could find the photo that was taken by a special multi-digit code. I could then order prints of the photo, if I wanted to, or have it made into special souvenirs. As soon as I got home, I completely ripped it to pieces and recycled it, of course.

I can only think that it is quite fortunate that I am the person who found the card and not someone else — the sort of person for whom we keep our children offline. Even if it were not such a person, the careless act of leaving such a card behind is just an invitation to your privacy to be decimated.

The simple solution is to be careful when you are given cards like these. They are not to be treated lightly and should be shredded unless you are like me and like to make souvenirs out of everything!