Yes others share your paranoia. If you are that
concerned get collectible insurance for it. Email
Brian Martines he knows of some good ones.

But in all honesty, cel image theft should be the
least your worries. If someone is going to take
the time to break into you’re apartment or house,
cels no matter how gorgeous you think they might
be, are not going to  a priority. Most thieves
like items that can be resold quickly for cash.
Say jewels, coins, cash, your atm & credit cards,
high end electronics, etc. Considering yours is
framed or will be, how many thieves would you
honestly imagine taking the time just to take your
dream cel? Be realistic, even if it was a pristine
Laputa or Mononoke production cel, most people
could care less. Cels probably do not interest
anyone except those of us IN the this maddening
obsession, otherwise, do you honestly think the
average person gives a frig? Lastly if you are
THAT concerned do not tell people you own a cel of
such quality, isn’t enough that YOU alone enjoy
it? I do not know about you, but I do not go
around showing what I have to total strangers, my
prerogative not to. If you want to, go on ahead
either in person or online,  but you never know
who might be watching/lurking.