I am pretty sure that most agencies can use this feature, so long as the programmer has allowed this feature to be initiated through the radios. For users who have the Model 2 XTS 2500's the only way a I-call or a page can be made with their radio is if the other users radio ID is programmed into the call list. And since the I-call feature is enabled in the system I don't see why there would be an additional charge. Radio's can also be paged through the system as well, The same process is done using individual radio Id's. But for users with the model 3 series radios, Any users radio ID can be selected by keying it in through the radio. These calls can also be monitored using a uniden BC-396XTL scanner with the I-call feature enabled. The scanner also has to be set to ID search mode, and not ID scan. This would be in comparison to radioshacks (wildcard) search. From what I have read though it seems that only the Uniden scanners allow this to be done. And you will only hear traffic from which the users radio has affiliated with. If someone is down in columbus and is talking to another user in your local area, you will only pick up half of the convorsation. From what I have listened to it seems that the private call's are used more than most people think. But with the capabilities of mobile phones most users just assume to use them, Which makes sence since making a call that way is secure.