The bat will get you problems from the police.
The telescoping steel baton , either16 inch ($15 on sale), or 26 inch can be held descretely in your pocket collapsed, eliciting no comment, until you need it (at which point a quick snap of the wrist extends it to full length). It is a great fashion accessory that should be part of every freeper's wardrobe
Just keep in mind that it can be considered a lethal weapon (as would be the bat) and aim for arms and knees and avoid the head.