I don't understand it. To access you funds at MyEtherWallet all you need is your private key. Let's say "
u4jk243khj23423h4ojij23i4j2i3j4o23pj4". That's it.
How can be this secure?

Somebody can write a bot, which will generate random strings (he knows lenght of string). And sooner or later it will match somebody's key. And since he doesn't need any additional password or account name, he will control that wallet.
How is that secure?
