City Of Chicago Website Target Of Cyber Attack?

A press liaison for Occupy Chicago praised the apparent hack in a tweet:

Rachael P @plussone

We <3 Anons! cityofchicago.org and cityofchicago.org #TANGODOWN @YourAnonNews @OccupyWallSt @OccupyChicago @CLOWNBloq
20 May 12