http://help.yahoo.com/l/us/yahoo/baseba ... AeHPS9jyN4
Fair Play and Sportsmanship
Even though fantasy games are meant to be a competitive experience for all involved, it is important to us that our users not lose sight of the rules of fair play and good sportsmanship.
To this end, each fantasy team owner agrees that, by joining the game, they will abide by the following regulations:
1. All league-related transactions will be executed with the intent of improving the owner's team and/or its standing within the league.
2. No owner may drop or "dump" players from their team for any reason other than improving their own team and/or its standing within the league.
3. No owner will engage in any action that may be deemed to be collusive (two or more owners agreeing to make moves that benefit one team, but not the other).
4. No owner will make any roster moves (including waiver claims, trade proposals, etc.) whose sole purpose is to hamper the play of other owners.
5. No owner will take any action whose purpose is to, in any way, interfere with fair play in a league.
not a clear cut no hoarding rule, but pretty much so.