I've witnessed stacks of cash far in excess of that.
However, when it is done, there is usually a fair bit of armament around the cash, and the kinds of people that keep that sort of cash on hand are also not the sort you want to commit an amateur robbery against.
When I was 12 y.o. I had that sort of money in my bedroom (years of saving money from my paper route job, and factoring inflation). Of course, I could prove that it was mine, but it seems like the bar is somewhat low if it's set at GBP1000. It's the kind of money that you use to pay to rent a cottage for your vacations, not ludicrous drug-traffic amounts ...
The only solution I'm coming up with would be to hand over control of your wallet to an anonymous-yet-trusted third party who's hidden behind Tor or such. The difficulty is in finding (or creating) an anonymous-yet-trusted party in the first place.