I'm on my way through Revelation Space, current listening to Redemption Ark. It's a great series for my daily commute!
It requires a malicious hypervisor, it seems? At that point it seems pretty hard to remain secure in the guests regardless.
tl;dr "Theoretically, yes [you can catch diseases from the toilet seat], but the risk is vanishingly low," says Jill Roberts, a professor of public health and microbiology. Also covering seat in toilet paper doesn't really work against germs.
Yum, looks great!