Woof woof, this is even broader in its warning than the classic post-war Austrian road sign.
I like the honesty though. "Watch out! Danger ahead! Be afraid! Be afraid of everything!". Or is it "Watch out! Danger ahead! Be afraid! Of something so secret and scary we can't tell you what it is!"?
You decide:
A computer thinks the following may also be of interest:
Maybe it's a ??M ??I? sign.
"Beware: Non-existence ahead"
[...] Calder has the road sign of the week – a good rival for the minimalist approach of this all-purpose sign near where I [...]
[...] round London, even if they are unlikely to rival this Austrian road sign for sheer information or this Islington sign for its summary of the modern malaise. But let's hope we don't end up with problems like this. [...]