Not even icecreamcow will know how to find the portals... I will be the only one who knows the formula to determine where they will be, so not even mods will have an advantage.
So... If I were to hack your computer, which I have no idea how to, I could steal the formula and determine where they are?
I have a solution, everytime someone finds a dragon tomb, they post a forum about it, a coords meeting place and then the whole group goes to the set place in a week. During the week, members can post on it saying: OOH I WANT TO COME!!! and just go! I mean, everyone gets a dragon egg in the end.
You'd also need to hack the servers to get their world seed, and hack the database to get the secondary seed.