This has got to be one of the most bullshit pieces of fearmongering, wrong-headed tripe I have read outside of a Bush presidency State of the Union transcription:
Wi-Fi piggybacking widespread: Sophos has revealed new research into the use of other people's Wi-Fi networks to piggyback onto the internet without payment. The research shows that 54 percent of computer users have admitted breaking the law, by using someone else's wireless internet access without permission.
According to Sophos, many internet-enabled homes fail to properly secure their wireless connection properly with passwords and encryption, allowing freeloading passers-by and neighbours to steal internet access rather than paying an internet service provider (ISP) for their own. In addition, while businesses often have security measures in place to protect the Wi-Fi networks within their offices from attack, Sophos experts note that remote users working from home could prove to be a weak link in corporate defences.
Stealing Wi-Fi internet access may feel like a victimless crime, but it deprives ISPs of revenue. ( remaining claptrap )
Sharing is not a crime; if I have a phone and am entitled to limitless free local calls, and if I choose to let my neighbor come over and make free local calls whenever they want, or even give them a satellite phone so they can use it without bothering me, that's not a crime. As for the EULA, I'd be hard pressed to believe it would hold up in a court.
I lock up my computers, but not my WLAN. I'm willing to let people use my WLAN as long as no-one goes crazy-abusive on it.Edit:
Apparently this is an IT security blog in the UK, where accessing a wifi network without permission is illegal. This is not /generally/ illegal in the USA, though there have been exceptions (see commments).