until recently this was the case – but the Police can take a digital photo with a helicopter flying overhead recording timecoded video and GPS locations with their footage of their evidence gathering team also taking the photos/videos (this is another reason why the photos are taken prominently by uniformed officers often wearing distinctive identification tabards)

Viewed together this is sufficient proof for Court that everyone was in the same place at the same time…

the use of ravers’ photos may be more problematic from a legal POV but ASBO proceedings only need the civil level of proof – plus as I mentioned previously modern cameras often store accurate timecode of their pictures; then you get people bragging on message boards about how big the party was, and even admitting to crimes/vandalism there….

This carelessness/arrogance – backed up with the evidence the cops have got with their own electronic surveillance; and witness statements from locals who complain about raves is plenty enough evidence for most British Courts…