(09-04-2011, 06:24 PM)Thomas Wrote: A website can't just login to say Minecraft or at least not to my knowledge. A user could also recover the account after having it sold, it's just the risk of transactions and no site can really prevent it.You can.
You can forward the data and then use a premium checker.
Premium checker: http://www.minecraft.net/haspaid.jsp?user=
Just make it submit the request with whatever the username is.