Ever heard anything so stupid

[neil2do]

Throughout the operation the police became aware that visitors to the Ace Café were warning each other of their [police] presence to circumvent the effectiveness of the police.'

  am sure its an offence to allow some one to break the law, 

[chaz]

Throughout the operation the police became aware that visitors to the Ace Café were warning each other of their [police] presence to circumvent the effectiveness of the police.'

  am sure its an offence to allow some one to break the law,

but it's not an offence to prevent someone from breaking the law? depends which way you (or the magistrates) look at it?