I'm just entering this new field of knowledge (Bitcoin), so I'm learning, didn't stop to read many things about this subject yet, but I'll learn more eventually, I was a bit concerned in fact, however as I see the answers here, it seems not the end of the world for me 
(sorry if it was a newbie question, but it matches with my status as member).
Oh well that does explain it. Just make sure that the next time you read most (if not all of the posts) before asking questions that might already be answered. Also as a average customer you should not really worry about these things; you can't really change anything either (since then you're most likely not a developer nor security expert). If you have questions feel free to ask questions in the Beginners & Help section.(sorry if it was a newbie question, but it matches with my status as member).