“Friends don't let jackasses drink and drive.”In sharing that tweet with a touch of the send key, film critic Roger Ebert joined the likes of Anthony Weiner and the 18-year-old from Radnor High School as the latest examples of the lack of online impulse control.Ebert was tweeting in reaction to the death of “Jackass” star Ryan Dunn, 34, in a one-car accident in Chester County, Pa., early last Monday. Whether his assessment was correct is beside the point. The timing — not even 24 hours after the deaths of Dunn and his passenger, 30-year-old Afghanistan war vet Zachary Hartwell — was “unseemly,” as Ebert himself later acknowledged on his blog.(The online reverberations in reaction to Ebert's tweet didn't exactly vindicate the social-media world, either. Ebert's Facebook page was flooded with vitriolic comments — and temporarily shut down as a result. Dunn's friend and “Jackass” co-star Brandon “Bam” Margera tweeted viciously and profanely in reply to the tweet, at one point telling Ebert, whose jaw cancer has left him largely unable to speak, to “shut your fat ... mouth.”)Former Rep. Weiner exercised similarly poor judgment in sexting with his Twitter followers. So did the Radnor High School senior who was charged last week with making terroristic threats in a video e-mailed to a school administrator. The video contains the words: “Cold metal in my hands / I am at school / I'll shoot you down / You stupid fool.”Just how far has technology upset our sensibilities? In Indiana, a 21-year-old Amish man named Willard Yoder was just arrested after allegedly sending 600 texts to a 12-year-old girl he wished to bed ... in a horse-drawn buggy. Thankfully, the girl notified her mother before he got his wish.So affixed to our bodies is the technology needed to tweet or post on Facebook that there is no longer a commonsense filter to save us from ourselves. It's as if social media have made mind-reading a reality. Gone is the deliberation that once was necessary to speak cogently, pen one's thoughts, or even dial a phone. In those instances, some level of forethought was necessary, affording the opportunity to catch oneself before committing bad behavior. Thoughts were just inner-held beliefs. No more.Now whatever is on the brain is almost immediately out for public consumption, etched in the metaphysical granite of cyberspace.Forget the carnival soothsayer who will read your palm and reveal that you're in a love triangle. Today, ESP begins with www. Suddenly, we're all wearing X-ray-vision glasses.Remember that plastic eyewear once sold in the back of boy magazines? They were often advertised next to the $5 kit that would explain how to change your banana-seat bicycle into a minibike. Those glasses carried the promise of allowing you X-ray vision. The fact that my parents told me they'd never work didn't stop me from trying. The prospect of seeing into people, reading their minds, has always had an allure. And now social media make it a reality because our iPhone appendages are at odds with common sense.Thank goodness that the most advanced technology when I was coming of age was the Xerox machine at the company Christmas party.Michael Smerconish writes a weekly column for The Philadelphia Inquirer. Readers may contact him via www.smerconish.com.