For example, a decker could run a program to return a list of SIC IDs/chrome serials within a certain range (maybe just the same room?), perhaps save those as devices, and use other software to damage that chrome or harm its owner. Maybe, for the sake of balance, there's a damage drop-off depending on the range from the decker at the time of execution. This could also open up avenues for chrome ICE. If you want it to just be limited to deckers, maybe a cracked gridterm can be vulnerable to delivering shocks either through the casing or a linked GridSight port.
These are just ideas I've had, I think I'd be pretty open to other forms of getting deckers more involved in biz. At the moment, while a huge improvement, deckers' utility is still pretty limited.