Starter line switch? Possible?

I was wondering if a switch could be implemented into the starter relay line somehow. I'm not to keen on how exactly they are wired up, and if I'm not mistaken, they have a lot of power going to them.

So would it be safe to try and make a switch to "open" the circuit as an anti-theft device?

use a relay

That's a word I used on paper when I wrote the idea down.

But is it possible? And safe?

I guess I have two options, put it before or after the ignition cylinder lock (key). I think after would be easier, since it is just that one circuit I want to mess with.

From wikipedia article...

to control a high-current circuit with a low-current signal, as in the starter solenoid of an automobile,

hahah, alright. thanks for the insight, Ima go get to work.

Brent Frankner has a writeup on his site on how to do this; Brent94Z on this site I believe.