backtrack-linux.orgは安全ですか？

Heck freaking yes! I love the tools provided by the site. I've been able to learn so much through and because of this site and its products (I say products because BackTrack comes with some additional first-party tools, along with third-party tools). Their wiki could use some help and expansion, but overall, the site is good. There is definitely a learning curve involved, though. You need to know your way around linux before you can fully utilize this distribution. The distro isn't intended for casual and everyday use (though some people do use it that way along with the way it's meant to be used). Like others said, there is a line between legal and illegal, but it's all based on how people use the operating system.

A line placed in between legal and illegal. peoples attempted to cross over each other with sacrifices. This Back-Track is a power to make differences. It is depend on how you use it, but remember, the greater the power you possessing, the greater the responsibility...

Pen test Linux distro. Very safe and trustworthy. Perfectly legal if used ethically, complete hackware if used illicitly. Also, pretty darn advanced, really geared towards IS professionals. Keep in mind, many exploits are done with legitimate tools. Most Password crackers will come up as hackware in your AV, but they are safe security tools. It is all about how/intent of use. Keep it ethical and use reputable tools like this suite and you are fine.