Very true. I've turned off recording of port scans and the like - I was getting too many to bother to report them.
The worst offenders, in my experience, both for port scans and spam, are Chinese, Korean, Japanese, and others from that part of the world.
Close behind come Mexico, Brazil, and Argentina.
Then, and probably ten to twenty a day on my machine, are from the infamous North American ISPs: Attbi.com, Bell.ca, Comcast.net, Pacbell, RR.com, and above all Verizon. I've sent them all frequent "cease and desist" messages which they've totally ignored. I assume port scanning and spam-sending is totally legal in the USA and nothing can be done about it.