THE NATION'S BORDERS, NOW GUARDED BY THE NET

Andrew Feldmar, a Vancouver psychotherapist, was on his way to pick
up a friend at the Seattle airport last summer when he ran into a
little trouble at the border.

A guard typed Mr. Feldmar's name into an Internet search engine,
which revealed that he had written about using LSD in the 1960s in an
interdisciplinary journal. Mr. Feldmar was turned back and is no
longer welcome in the United States, where he has been active
professionally and where both of his children live.

Mr. Feldmar, 66, has a distinguished resume, no criminal record and a
candid manner. Though he has not used illegal drugs since 1974, he
says he has no regrets.

"It was an absolutely fascinating and life-altering experience for
me," he said last week of his experimentation with LSD and other
psychedelic drugs. "The insights it provided have lasted for a
lifetime. It allowed me to feel what it would be like to live without habits."

Mr. Feldmar said he had been in the United States more than 100 times
and always without incident since he last took an illegal drug. But
that changed in August, thanks to the happenstance of an Internet
search, conducted for unexplained reasons, at the Peace Arch border
station in Blaine, Wash.

The search turned up an article in a 2001 issue of the journal Janus
Head devoted to the legacy of R. D. Laing, with whom Mr. Feldmar had
studied in London about 30 years before.

"I traveled to many regions many times with the help of many
different substances," Mr. Feldmar wrote of his experiences with Dr.
Laing and other psychiatrists and therapists. "I took peyote,
psilocybin mushrooms, cannabis" and other drugs, he added, "but I
kept coming back to LSD."

He was asked by a border guard whether he was the author of the
article and whether it was true. Yes, he replied. And yes.

Mr. Feldmar was held for four hours, fingerprinted and, after signing
a statement conceding the long-ago drug use, sent home.

Mike Milne, a spokesman for the Customs and Border Protection agency
in Seattle, said he could not discuss individual cases for reasons of
privacy. But the law is clear, Mr. Milne said. People who have used
drugs are not welcome here.

"If you are or have been a drug user," he said, "that's one of the
many things that can make you inadmissible to the United States."

He added that the government was constantly on the hunt for new
sources of information. "Any new technology that we have available to
us, we use to do searches on," Mr. Milne said.

Mr. Feldmar has been told by the American consul general in Vancouver
that he may now enter the United States only if he obtains a formal waiver.

"Both our countries have very similar regulations regarding issuance
of visas for citizens who have violated the law," the consul, Lewis
A. Lukens, wrote to Mr. Feldmar in September. "The issue here is not
the writing of an article, but the taking of controlled substances. I
hear from American citizens all the time with decades-old D.U.I.
convictions who are barred from entry into Canada and who must apply
for waivers. Same thing here."

The waiver process would require a lawyer, several thousand dollars
and dishonesty, Mr. Feldmar said. He would have to say he has been
rehabilitated.

"Rehabilitated from what?" Mr. Feldmar asked. "It's degrading,
literally degrading."

Ethan Nadelmann, the executive director of the Drug Policy Alliance,
which works to ease drug penalties, said Mr. Feldmar's case proves
how arbitrary American drug policy can be.

"Roughly a majority of the population of the United States between
the ages of 18 and 58 has violated a drug law at least once," Mr.
Nadelmann said, and there is no reason to think that Canadians and
other foreigners of a certain age have experimented much less.

It has been a long, strange trip from the Summer of Love to the Age
of Terror, from excluding people based on actual criminal convictions
to turning them away based on a border guard's Internet search. The
first approach is rooted in due process and enhances the nation's
security. The second is profoundly arbitrary and effectively punishes
not past drug use but honest discourse about it.

"I should warn people that the electronic footprint you leave on the
Net will be used against you," Mr. Feldmar said. "It cannot be erased."