This is discussion archived from a time before the current discussion method was installed.
: An algorithm I discovered and tested in junior high: Walk (don't run) towards the person with the item. They'll throw it to someone else; ignore that. Hit the person who HAD it, hard. Pain is better for this than actual damage; a bloody nose is preferred over a broken arm. Walk towards whoever has it now, asking nicely if they will give the item back to you. Repeat until you have the item. If the latest target tosses it away (not to another person) make them go get it.
I found it took three iterations at most...