google.com é seguro?

Overall I don't think it's "dangerous" to use Google, however be on your guard. Nothing is "free". Google makes its money by selling all data on what you do to third parties. Some of their services (like doubleclick for example) are considered as "spyware" by some famous spyware scanners (like "spybot search & destroy" for example). If you don't mind Google doing this, then I don't expect much harm for you when using Google. If you are against such practise, you need to avoid Google and I'd also advice you to have a tool blocking advertisements as most sites use Google for this and thus you'll be tracked. One thing you cannot blame Google for. Google is in the first place a search engine and some results popping up can be dangerous. If Google knows about that they'll most likely remove that, but the amount of sites like this grow faster than any Google employee can keep track of, so be wise in what you click. This goes for all search engines though.