With its bright villas, personal butlers, and exquisite saltwater lagoon, the resort was certainly luxurious enough. And surrounded by water, the St. Regis Resort on the island of Bora-Bora in French Polynesia, was inherently private. But when Gary Mansour, co-founder of the Beverly Hills-based Mansour Travel, sent one of his high-profile clients there last year, he still faced the challenge of making sure it was paparazzi-proof.

The solution: The resort’s well-connected owner arranged for a no-fly zone over the facility. “I’d never asked for that before,” Mansour says, “but I do now.”

It’s just another tactic, he explains, in the battle to safeguard the privacy of well-known clients. This effort been stepped up in recent years because of post-9/11 security concerns; the voracious, 24-hour-a-day appetite for celebrity news; and the increasingly intense, global nature of business competition. That Brangelina or Tony Blair would want to be shielded from prying eyes is a given. But now even those who aren’t household names are demanding more privacy—and are willing to pay a high price for it.

And the hospitality industry is responding to the demand. “Hotels have definitely been increasing their facilities for security and privacy,” says Albert Herrera, vice president for hotels and resorts at Virtuoso, a consortium of high-end travel agencies. “They’re building larger suites to incorporate security personnel, with private lifts to take guests directly to those suites, taking on the resources of a third party to do official security sweeps in the suite and around the hotel. It’s not just about opulence anymore; it’s about security and discretion.”

For those who have made the requisite arrangements, privacy protections kick in the moment a reservation is made—often under an alias. Rooms are sometimes paid for under the assumed name, even if it means misleading an accounting firm representing the guest. “Leaks can occur anywhere,” Mansour explains.

Clandestine arrivals and departures are crucial. Staging them can resemble a commando mission. Hotels such as the Lowell in New York are prized for their minuscule lobbies, where limited space discourages anyone—even other guests—from gawking. Others, such as Berlin’s Hotel Adlon Kempinski and the Waldorf Towers in New York, have underground garages with access to private elevators. And some offer alternate entrances, whether from a helipad or the less-than-glamorous rear loading bay (the Peninsula in Hong Kong, for example). “We have several options,” says Geoffrey Gelardi, managing director of the Lanesborough, in London. “The front door [opening into a small lobby with elevators], a door on Grosvenor Crescent with a lower-level driveway leading to the elevators, and an underground option. So we can be absolutely sure that no one will see a guest arrive.”

Once high-profile guests are inside, keeping their presence hidden requires careful orchestration. The staff of the Carlyle in New York, long known as a bastion of privacy, routinely juggles the assumed names of a number of patrons. “Keeping them straight is a job in itself,” says a former employee. “Assigning the right pseudonym to the right guest can get rather confusing.” Some hotels also help conceal identities by managing confidential documents (they’ll provide a shredder on request or arrange for the general manager to handle the papers).

To maintain privacy, Mansour often requires nondisclosure agreements from hotels. The Lanesborough’s Gelardi asserts that the establishment’s butlers, who tend to guests, would be harshly dealt with if they let confidences slip. At another icon of privacy, the Hotel Bel-Air in Los Angeles, a pool attendant was dismissed after revealing to the media a guest’s presence at the hotel, general manager Carlos Lopes explains. The hotel’s famous oval pool is an especially sensitive area; guests aren’t even allowed to take pictures of other patrons there.

To separate high-profile customers from other hotel guests, premier suites are often located in special wings, with access restricted to these select residents and their staff. At the Waldorf Towers—which has hosted royals, business leaders, and every U.S. president since Herbert Hoover and turns into diplomat central when the United Nations goes into session—no one gets onto the floors of the 26 premier suites without a special elevator key. Security personnel are posted outside the doors of dignitaries.

Perhaps the most secure hotel accommodation in the world is the Adlon Kempinski’s presidential suite, a 4,520-square-foot complex. Opened last year, the suite is in a separate wing with two private elevators leading to an underground garage. It even has rooms and a lounge for bodyguards and staff, armored doors, bulletproof walls and windows, and its own power supply and telecommunications system.

The suite offers all the privacy and security you could want in a room—plus, while barricaded inside, you’ll have a postcard view of the Potsdamer Platz.