There is a disclaimer on the mod, saying if the owner wishes to do so he can make it impossible to download it. This mod does communicate with the server for permission checks. These are intended to add permission requests to the mod to adress the concerns some server owners have about misuse. A few servers do automatically ban users when it detects the mod being installed; while I do not support this action in any way, it is important to be wary of the fact that some servers do this. The vast majority, however, either do not use this system or implement the in-mod permission request system. Please contact a moderator on your server for details (they generally like being notified before you install the mod as to what you wish to download).