Why? Looks like they're doing realtime network monitoring for security purposes. Sounds like a high performance application to me. Haskell has a reputation for being slow, but the proof is in the pudding - and what's being asserted is that a stronger type system enables better optimization.

Interesting - I didn't realise the performance of a system was measured in how "obscure" the source language is.

(edit: I am Australian - this is sarcasm.)