safety

Linux isn't targetted by the malware writers - presumably because of the small user base but also Linux has more security built in to start with.
The only real danger is from rootkits - these do exist for Linux systems but are almost all targetted at older software running mostly on servers.

Spyware is a very wide term and you could say that Linux is susceptible to some spyware types - depending on what programs you run. For example, the somewhat intrusive LSO's used by many sites these days are happily stored on your system if you have the Adobe flash stuff installed and they are not deleted by removing cookies in the usual way.

As with any operating system, you should always be careful when browsing the interwebby and use sensible tools such as NoScript with your browser to prevent issues arising.

But in the main, Linux systems are much less at risk than Windows ones.

Chance that you will pick up a virus on GNU/Linux OS is probably one in a million, while there are over 100000 viruses for Windows OS.

http://www.cknow.com/cms/vtutor/number-of-viruses.html