Security now
After listening for over week to Security Now! podcast (thanks, Steve, thanks Leo and happy birthday), I've decided to actually do something about the security on computers around. I started to scanning my home network using "Shields Up" and was happy to found that the only open port was SSH, exactly as I thought I configured it.
As next step, I followed the advice from this podcast and used my hosts file to block out ads servers and other internet vermins.