He says they are for bird food so he can sell them legitimately. If he said, " HEY GUYS THIS IS SO YOU CAN GROW BIG BUDS! " well ebay would take it down in a heartbeat. Honestly - you just have to talk to him and if you trust him - ask him the germination rate. People sell all sorts of stuff on there - freaking hawaiian baby woodrose and mushrooms - they state stuff like - for flowers, for scientific analysis, etc so it looks legitimate.
I can see it now...
Dudes in a cell and Bubba asks what he's in for.
"I saw an ad on ebay selling seeds, so I bought some" Dude replied. "The fuckin' Cops set me up!!!"
Bubba kicks dudes ass for stupidity on general principle.
On a serious note, I get bird seed that has hemp seeds in it, supposedly irradiated and sterile. But I have heard that some folks have tossed out their birds seed trays, only to discover a cannabis plant or 2 growing where they emptied. Go figure!!