Protection of privacy and freedom of expression are basic, but not absolute rights. They have limits, which come into play at the point where one person's freedom causes harm, or infringes on the rights of somebody else. Shouting "fire" in a crowded theatre cannot be defended on the grounds of free speech because it could create panic, possibly even a riot. Similarly, as the unhappily exposed chatterers have discovered, using a pseudonym doesn't mean you can say whatever you like about a person or a company with impunity. Libel is still libel, even on the World Wide Web.
Only a court can decide where the contentious criticisms fall on the wobbly continuum between fair comment and libel, but the case has already called into question the balance between anonymity and accountability in cyberspace. Using a pseudonym seems to be fine, but surfers are still responsible for the words and opinions they utter. If they cause offence or material damage, the injured party has the right to seek redress. Since confronting one's accuser is a basic principle of natural justice, that seems to imply knowing his or her identity.
Besides, what's the point of anonymous accusations? They slither in the underworld of rumour and innuendo. A real name adds conviction, credibility, and moral authority to a denunciation, as Zola showed a century ago when he published "J'accuse", his ferocious condemnation of the French general staff for charging Alfred Dreyfus, a Jewish army officer, with treason. Of course there can be unexpected consequences in seeking legal redress. Zola was prosecuted for libel and found guilty. He won on appeal and fled the country before a retrial.
History has vindicated Zola and exonerated Dreyfus, but Philip Services Corp. might be well advised to think carefully before proceeding any further against the unmasked chatterers. In recent times Philip has suffered losses of $126.3-million (U.S.), a copper-trading scandal, and the departure of most of its senior managers. By taking legal action, the company has drawn attention to its troubles and perhaps given the criticisms more credibility. Before embarking on the next logical action, which is to accuse its critics of libel, Philip might do well to remember the sorry history of Oscar Wilde, the Anglo-Irish playwright. After being publicly insulted by the Marquess of Queensberry, his young lover's father, Wilde brought suit. Instead of protecting his reputation, the ensuing court case demolished it -- at least in Victorian society. Accuser beware seems to be a good rule to follow in both the wired and the unwired worlds.