Let's paw through some recent reader e-mail . . . with full confidence that nary a one is a fake or forgery.A column about\u00a0the proliferation of self-checkout lanes at groceries and retail outlets\u00a0elicited many complaints - about those lanes, not the column - as well as this interesting social theory from reader Mike Ryan, who in 1973 helped install what was then only the fifth supermarket bar-code scanning system in the U.S."I find interesting the juxtaposition of your article with the recent release of the movie 'I Robot,'" Ryan writes. "If you read Isaac Asimov's entire robot series, one underlying theme is humanity's use of machines [computers, video telephony, robotics] to isolate themselves, one from the other, until in the end they abhor actual face-to-face human contact. [Are self-checkout lanes] one more way to isolate ourselves, through machines, from human contact?"Interesting question to ponder in an e-mail exchange, no?A hand-wringing column about\u00a0unethical Internet practices\u00a0drew protest for citing as an example an acquaintance of mine who "shares" his Netflix membership with another family - the point being that this is unfair to Netflix."Given that Netflix only lets you have three DVDs out at any one time, it doesn't seem to matter how many folks you let watch them," writes Eric Woodhouse. "If that were an issue, they'd have different pricing schemes depending on how many people were in your family, right? Seems to me that there's a big difference between sharing a given DVD [or videotape, or CD or library book] and making copies of same to distribute."I was hoping to hang my defense on the Netflix acceptable-use policy, but the company hasn't replied to my inquiries. Until it does I'm waving the white flag.My doubting the effectiveness of\u00a0a new federal law that increases jail time for identity theft\u00a0brought a separate criticism of the measure that I wish I had thought of myself."The Identity Theft Penalty Enhancement Act is almost pure posturing on the part of politicians," writes Karl Compton, "since most identity theft isn't prosecuted by the federal government. It is mostly prosecuted by state and local authorities."That same column brought this unrelated reader gripe:"While we stone the identity thieves and the phishers, can we get the word out to legitimate 'trusted sources' that when they send us an e-mail they need to properly identify themselves in the 'from' field?" asks "Dennis in Austin." "Today, my hosting company sent an e-mail to inform me that my Web address registration was coming up for renewal. It came from 'Cindy' . . . not 'Cindy@yourtrusted source.com,' just 'Cindy.' Despite an otherwise legitimate-sounding subject line, I'm as likely to wholesale delete such an e-mail with all the others that get through my Yahoo filter. (Fortunately, I didn't.)"Finally, my opining that the CAN-SPAM legislation "hasn't been worth a tinker's damn in terms of canning spam," prompted an e-mail with the subject line: "Tinker's dam.""Yes, that's 'dam' and not 'damn,'" contends Charles Joeckel. "A tinker's dam was a small circle made of mud that a tinker [one who repaired pots and such] could use to melt the lead and\/or pewter used to make repairs. The tinker would make the dam out of the dirt found at hand and discard it after each melting."So says Joeckel. My American Heritage dictionary - which I don't mind noting that I consulted before filing the column - cites "damn" as the more common variation, while also accepting "dam." And it offers a markedly different etymology than does Joeckel: "Probably from the reputation of tinkers for cursing."I like Joeckel's better. More colorful and makes more sense, plus I cannot imagine what it was about pot repairmen that would have caused them to become notorious potty-mouths.Send more. The address is firstname.lastname@example.org.