Well they could, but why would I give them If I seriously had something dangerous in my PC? Though I've secured my system more for theft, though It would be goo

Well they could, but why would I give them If I seriously had something dangerous in my PC? Though I've secured my system more for theft, though It would be good to have guest account which could login normally, so that the thief would not just reformat the drive right away and I could actually trace the thief when he's using the PC before reformatting like some of the success stories, but more than that I don't want my files to be seen.