heres what i found in their html now google what spylog is http://www.google.com/search?hl=en&q=spylog&btnG=Google+Search
3FN is a PPC network that has thousands of publishers and advertisers, do you think they would risk their entire business by playing with dangerous cookies? Get a grip man. Ugh, like I said before Spylog is a statcounter. See their website here (translated).
Well just cause your that naive into believing that doesn't mean other people will be the same way. Everything I've stated was clear evidence to be cautious of , if you don't like what I have to say then don't bother responding.
Other than Spylog being perhaps a confusing choice of brand, there's nothing to worry about here. Like checksum said, its just a stat counter. If you're afraid of the "security and privacy risk" that cookies may pose, just switch them off (although it will cut off your ability to log in to virtually all websites with registration).