Is there a wipe out program

Okay, here's my question in detail.

I am a 70 year old Father and Grandfather. I'm gay, been gay all my life and my children know it. I have a computer which I use for everything. I have all it's programs backed up elsewhere. But, as a gay man I have things on this computer I do not want my children or, worse yet, an inquisitive grand child to see. No, there is no kiddy porn or anything like that, I have other tastes and I have a collection of stories, etc.

So, is there a program out there that could be installed on my computer that, if I were hospitalized and one of my children or grandchildren became inquisitive and tried to turn on the computer, that if they did not have the correct password, the computer could whip itself out if they tried, let's say three times?
If you need anything more, just ask

Note: This post was edited by a forum moderator to remove exposed email address to prevent spam and abuse by others on 09/05/2012 at 2:23 PM PT