I work in the IT industry. I grew up around computers and the Internet is part of my daily life, both at home and work.
Out of all the projects, websites and applications that I've come across, Wikipedia is one of the greatest and most open tools for collaborative information gathering and sharing in my opinion. Essentially, this is what the Internet was made for.
As with everything upside, there are downsides. Openness and trust can be easily misused and abused. For every good person out there, there is a bad one. Just like life, heroes and villains are constantly at odds.
