Maybe it’s time the landmark “H-0-L-L-Y-W-0-0-D” sign was changed to “U-N-C-I-V-I-L.” Like never before, it seems, the powerful barons of global popular culture are hanging out the dirty laundry. Sure, verbal mano a mano among showbiz moguls is Hollywood tradition. But the recent rounds of public roughhousing are extraordinary. Why? Thanks to merger mania, a handful of hypercompetitive megamoguls now are crowded into the same sandbox, and the testosterone levels have overflowed it. “The pressure and stress gets to them. It’s not the same as being in the asparagus business,” says Jack Valenti, head of the film industry’s trade group. And with today’s saturation media coverage of the biz of showbiz, the tart-tongued feuds of Tinseltown’s titans get aired more than ever.

Some of the bluster is especially abrasive. Last week NBC’s top West Coast exec, Don Ohlmeyer, squawked about Michael Ovitz, the former talent agent who’s now No. 2 at Disney, owner of ABC. “Ovitz is the Antichrist,” he told Time magazine. Some NBCers, it appears, believe Ovitz was behind a scheme to pry loose a top NBC programmer, Jamie McDermott. The supposed plot involved McDermott’s trying to break her NBC contract by accusing Ohlmeyer of sexual harassment. Ovitz won’t comment. Ohlmeyer and McDermott have denied any sexual harassment.

Over at Viacom, mogul Sumner Redstone also administers public thrashings. In a lawsuit, he slimed cable titan John Malone of TCI when the two faced off in the battle for Paramount: “In the American cable industry, one man has … seized monopoly power. Using bullyboy tactics and strong-arming of competitors, that man has inflicted antitrust injury on virtually every American consumer of cable services. . . . That man is John C. Malone.” Even loyal employees can feel Redstone’s bite. In January he abruptly fired Viacom’s popular CEO, Frank Biondi, deeming him not aggressive enough. Or as Redstone said to the press: “Frank’s style doesn’t work in this company as it is today.” Now, in another public spat, Redstone is blocking Biondi from taking the CEO job at Edgar Bronfman’s MCA in a bid to win business concessions from MCA.

For sheer entertainment value, nothing top-, the mudslinging of Turner Broadcasting’s Ted Turner and News Corp.’s Rupert Murdoch. When Murdoch recently threatened to take on Turner’s CNN Turner talked of “squishing Murdoch like a bug.” Murdoch retorted: “Honorable sir, it’s true that I am a low, mean snake. But you, sir, could walk beneath me wearing a top hat.” Federal regulators sometimes are targets. Not too long ago TCI’s Malone mused in an interview about how rubbing out Federal Communications Commission chief Reed Hundt might benefit cable. “All we need is a little help. … You know, shoot Hundt! Don’t let him do any more damage.” He later apologized.

As Disney prepared to fend off Katzenberg, some old hands recalled the other day that this month marks the third anniversary of another spat: CEO Eisner vs. Time Warner CEO Gerald Levin. The spark: taunting TV ads by Levin’s camp. In one swipe, Eisner questioned Time Warner’s “corporate direction” under Levin, who he also didn’t think measured up to Time Warner’s last chief, the late Steve Ross.

Do the moguls think all the sliming harms the industry? Last Friday they had no comment or were unavailable. But clearly, all the incivility comes at a bad time. The execs are facing political pressure to clean up their TV shows and music. And some have mergers up for regulatory approval. So maybe the moguls should hire a charm consultant, clam up in public and say nice things about each other to the press …

Nah, sling away.