"Why is mudlarking becoming more popular in London?" ask the BBC
The treasure hunters of the River Thames (16 February 2017). Probably because the selfish want to get 'their share' before its all gone:
The beeb world service reporters were on the foreshore back in the 80s trying to get voice recordings ..But I told em to P**s off as did other diggers at the time ..Why would we want to advertise our hot sites which are now picked clean as a buzzerds (sic) bones ..(post by 'Targets' Sat Feb 18, 2017 12:02 pm my emphasis)
The archaeological record, of London too, is a finite resource. Once it is gone it is gone.
Hat tip Nigel Swift