Crackability of a software

Hi folks.
I start saying that in my opinion all softwares are crackable (not in all cases, for example i think that a keygen is not always possible, but, imho, a patch is always possible). Is this right?
If my first statement is right, is there anyone that knows a site that says what i've said before (a site such as intel, microsoft or companies like these)? Also is possible to prove it?