Talking about DPI - here is one outfit (advertising that it uses DPI for this purpose) to look out for that has already been involved in the ACS story.
http://ng3sys.com/products.jsp
run by Alireza Torabi who has apparently provided harvested IP data to Andrew Crossley of ACS in the past.
There is a long and complicated story involving him, Andrew Crossley, Terence Tsang, and a variety of legal firms who are queuing up to get on the "speculative invoicing" gravy train while it is still on the rails (derailment due when Digital Economy Act provisions come in, if they do).
All out there now in the ACS email trail apparently.
Tomorrow is the key day to see what happens to the Gallant Macmillan NPO hearing before Chief Master Weingarten.
Will Plusnet be legally represented?
What will the judge say and do (the case has already been adjourned once, and PlusNet are rather late with their objections)?
When will Gallant Macmillan's website get back on line (disappeared about midday today having been slated for a DDOS attack by 4chan)?
When will the various civil actions start against the ISPs who definitely released unencrypted data to ACS, and against ACS who allegedly sent all sorts of details in emails including unencrypted credit card details linked to names, addresses and IP addresses?
What criminal DPA prosecutions will result?