As of November 2014 the toll booths at the Dartford Crossing (comprising of the Dartford Tunnels and QE2 Bridge) were removed and replaced with a number plate recognition system to automate the charging for the crossing.
However the signage that has been put in place is exceptionally poor and many motorists are being sent penalty tickets for non payment of the tolls despite no sign making any mention of the word "TOLL".
This video driving from Essex into Kent over the QE2 bridge of the Dartford Crossing shows how lacking the signs are - the only overhead gantries show a large C symbol yet no mention of any Toll or charges so it's hardly surprising that people outside the area have no idea that they are meant to pay for using the crossing.
Anyone who has received a Dart Charge Penalty Fine and wants to appeal is welcome to use this video as evidence to support any appeal that the signs are insufficient to support charges.