I get my seeds from Amsterdam...NEVER had a problem(except for paying a little more,damn dollar).
It takes about 4-5 weeks ,mine came in taped inside a greeting card.From a secondary address(not were purchased from).
IF...that is a big IF customs happens to open it and find the seeds all that would happen is they would be confiscated and a letter would be put in their place to tell you that they had been confiscated.
They will not come after you..repeat they will not come after you for seeds,they are looking for muich bigger things and wont waste the time on you....trust me.
Now i have heard of problems from Canada and Britan..you need to be more carefull buying from there as the customs is tighter because of our wonderfull friendly goverment dea thats friend with our close niebors...and i have heard of more people getting ripped off from those countrys too.
Good Luck with your grow !