IT SOUNDS McCrazy. In an arguably unrivalled example of corporate paranoia, McDonald's, a giant hamburger chain, has forced a tiny health-care company based in Switzerland and calling itself McWellness to change its name.

It is one thing, of course, for McDonald's to defend itself against a shoddy hamburger joint brightening up a greasy shopfront with a pair of golden arches, or pinching the “Mc” prefix to piggyback on its reputation for consistent standards. Even here the Oak Brook-based multinational has been a touch ruthless. It has sued a sausage stand in Denmark called McAllan's, a coffee shop in California run by Elizabeth McCaughey, and McMunchies, a sandwich shop in Britain.

It is another thing, though, to send packs of lawyers after a company that offers Internet-based medical services to corporate executives. Of course, the Internet makes it easy for trademark harassers to flush out offenders. But McWellness's rather silly name had nothing to do with McDonald's anyway. Its genesis was McKinsey, a management consultancy where its two founders once worked. Barbara Staehelin, one of them, says she wanted a name, like McKinsey, that promised global standards, although she admits that reference to a McDonald's burger “works just as well”.

The puzzle is why McDonald's would bother with this loss-making small fry employing only 45 people. In a letter to the American patent office's trademark trial and appeal board in January, McDonald's lawyers complained that allowing the use of McWellness or alternatives like McDoctor or McMedicine “will create confusion and will cause damage to its (McDonald's) hard-earned goodwill.” Would McWellness, which last month gave in and renamed itself GetWellness at the cost of some $1.8m, four times its annual revenue, frighten patients with dark tales of cholesterol in Happy Meals?

Perhaps, though, McDonald's has more ambitious plans. Clues lurk in the vast array of non-food related trademarks registered by the company—McTravel and McSpaceStation among them. It even claims to own the phrase “Immunise for Healthy Lives”. The company admits that its future plans “are not limited to food”.

Before it got nasty, McDonald's considered taking a stake in McWellness. Tellingly, in their letter to the patent office, its lawyers predict that McDonald's will “likely expand the use of its ‘Mc' formative marks to include the same services on which the McWellness mark is intended to be used.” Reconciling burgers with health care might prove a stretch. But McDonald's seems ready to give it a try. Where there's “Mc”, it doubtless believes, there's brass.