Just like New York City, you can find all kinds of cool things on the internet. And, just like New York City, there are all kinds of scams and tricks that you need to be aware of. Many of these things are the kind of thing that you can detect if you keep your eyes half open.
One of the more common things that happen is when you download and install a legitimate program, the installer also (quietly) asks you if you want to install something else. This is typically a toolbar for your web browser,1 but lately another common one is McAfee Viruscan. Any time a program or website requires your email address, look for a way to disable automatic email communications like newsletters (this is often enabled by default). If it’s not required, I don’t provide it.2
As I said before, this is not uncommon when installing even legitimate programs. Again, like New York, the main key is to keep your eyes open. I have come across a couple websites that explain some of the tricks that are used:
I highly recommend everyone reading through both of these sites… and keep your eyes open. You don’t need to install another toolbar.