Think about that for a moment.
Will they find out about a case mod? Probably not, but it is still the principle of the whole thing. You bought it, it is yours, end of story. Sony doesn't like you modding or hacking, then ban your PSN account.
Unless of course instead you want them to rightfully kill consoles.
Just hope you don't end up as one of those "victims of the system" who do nothing wrong but somehow end up with an unfixable bricked console because guess what, it will happen.
as you said in the post above this one, "I think people are getting paranoid ..."
putting an option to install linux on the ps3 in the first place was the biggest olive branch in the world sony could have done to the hacker/homebrew community to let them run their custom code on a ps3.
but despite that they gave sony the finger anyways -- first with the other OS overflow bug then by deciphering the ps3's security key.
hell, sony also lets you use a standard HDD to upgrade your system unlike the 360's proprietary drive.
sony doesn't give two-shits if you mod your consoles casing and it is ridiculous you'd even think they every will. sony is trying to protect the billions of dollars in investment they've put into the ps3 and rightfully so.