A problem about " media mail " shipping

I was told by my post master that the USPS can open ( not x-ray ) media mail packages/mailers at random and inspect for non-media mail. I asked her why and she said " because of the low cost of shipping by media mail ". So then i asked her what was found in some media mail shippments " I have heard of baby snakes and spiders in VHS cases/sleeves among other things ". I 'm concern that my eBay stuff like old monster magazines, comics and VHS tapes could be damaged because of the opening and resealing. AND I thought that mail is private from the mailer and reciever. Has anyone one else heard of this and what do you think about this ?

Thats correct , I sell books online and have been inspected more than once. It really gets me fired because I take extra care to protect my customers books from the elements. They take a box cutter and start cutting away with total disregard for your product . I once had a clerk ask me why I would double box books. When I asked that the postmaster to come to the counter to inspect my books for damage due to her disregard . I made her aware that these books are $100.00 each and due to the fact that there were 30 of them if that box cutter cut through the bindings she would be responsible for $3000.00 she got a real attitude. Then I demanded a roll of their tape and I would repack them myself due to her piss poor attitude. I would highly recommend if you dont want them hacking away at your items, To take the box unsealed and let them inspect and bring your own tape and then seal it up after inspection. There is a sign right on the counter at our post office that says media mail subject to inspection.