Programs have bugs, or issues, as they are commonly called, which is the result of their being made by people, which are also not perfect. The main issue with spyware is that entirely too many people are unaware of how they get it, and not to mention the fact that some types are entirely too easy to develop. Google has a large amount of potential for datamining, which I'm positive that they already use anyway. A search engine is only as good as the relevance of the data, and because of this they need to maintain what data is relevant to the most people in order to make that a priority. This is known as job security. The potential risks of this activity are phenomenal. Because of the massive amounts of information maintained by the people at Google, it is entirely possible that if their system were compromised millions of people would have information available to people who don't really need it or have the real right to access it. Gmail accounts, etc. will all be included in this. If users are afraid of spyware, I have one solution, use a text based browser such as lynx. Ohh and another thing, firefox happens to be open source and the development of it is much faster and more active than it is for IE. So that if some code is found to be vulnerable they could, in theory, patch it to fix that portion of the code before the vulnerability to spyware could be taken advantage of. One thing that it is important to remember is that Firefox moves at the speed of open source and IE moves at the speed of snails.

Every piece of software that has/will ever be made will have bugs, lots of them, its the speed with which they are dealt that makes all the difference