Confiscation is small change. Customs can(and has) notified local law enforcement in certain cases of an attempted seed delivery to a given address.
There are a small number of cases where LEO has 'stopped by' at that address, and spotted something 'suspicious'. Searches and arrests have happened. Seem to be very rare, but have happened.
If you open your door to a LEO, they can claim they smelled the odor of cannabis, and they have a warrant less search.
Wow, and here I had 10g's worth of roids snapped at the border over two shipments, and I got a nice letter on yellow paper saying my items were seized as suspicious goods, if I thought they were seized in error, I could go to thier office to claim it.....
maybe the people you heard about who got pinched actually went to pick them up.
It's entrapment if they end them through and then stake you out to arrest you.. and guess what, if you get a package that's been opened by customs and delivered, use your head, throw the things out and don't grow for a while then.. either way, pretty common sence. You won't get in shit. I'm talking from experience over a pretty serious charge, and all I did was change my address with the place I bought the roids from -$32 and a private mailbox from mailboxes inc, and I was back in business.
I'm not saying it's never happened to anyone, but point me to a case study or a newspaper article about it, and I am sure you will discover there was more to it then someone buying seeds online..
As a side note, if you get your package of seeds that's been opened and sealed with yellow tape indicating, by law, that it was opened for inspection by customs, and you know it's illegal, common sence would dictate you would either throw the seeds in the garbage, and not grow for a while.. or take the seeds in to the cops yourself, and tell them you don't know what they are, but you think after looking on the internet that they could be "cannibas seeds".. that's not going to work though if you go in stoned wearing a 4:20 shirt and have dreads down your back.. again, common sence would come into play as with any situation.