This is a feature of 7.0. The ACL capabilities were expanded into "firewall rules" and "firewall policies". Every firewall rule has a source, destination, application, effective time, direction and response (block, allow, inspect, drop - and whether to send the data to syslog).
The firewall rules are under Configure -> IPS Settings -> Policies -> Firewall Policies.
You also have to define a firewall policy on the interface before it will take effect.