First, the section of the Code of Federal Regulations that it is referring to is Title 14, Chapter V, Section 1211.  Title 14 is the part of the code dealing with aviation and space and sections 1211 through 1299 specifically regulate the National Aeronautics and Space Administration (NASA).

Section 1211 was added in 1969 when the U.S. would be bringing a space vehicle and astronauts back to earth from a mission to the moon.  The section was designed to protect the earth from any contamination that may have been picked up during the trip and did not specifically describe contact with alien beings or UFO’s. The wording from Section 1211 part 100 says, ” NASA policy, responsibility and authority to guard the Earth against any
harmful contamination or adverse changes in its environment resulting from personnel, spacecraft and other property returning to the [earth] after landing on or coming within the atmospheric envelope of a celestial body…”  There is no mention of alien beings or vehicles.

Section 1211 was taken out of the Code of Federal Regulations in 1991.  An announcement in the 1991 code says that the section was removed “…since it has served its purpose and is no longer in keeping with current policy.”

A complete reading of the regulation makes it clear that it applied to any manned or unmanned space mission that lands or comes within the “atmospheric envelope of a celestial body.”  That would apply to anyone who has been into space, not all American citizens.  It didn’t prohibit contact with extraterrestrials.  It merely specified what regulations would affect a mission’s return to earth to protect us from space contamination.

Also, although the government has denied that there have been known contacts with extraterrestrial beings or vehicles, there has never been, to our knowledge, a governmental position that there could not be.  The NASA Origins Project, for example, includes the search for any life outside of our planet.  According to NASA, the project is designed to explore two questions: Where do we come from and are we alone?

AND….

EXTRA-TERRESTRIAL EXPOSURE LAW

  ALREADY PASSED BY CONGRESS

     _________________________________________________________________

   On October 5, 1982, Dr. Brain T. Clifford of the Pentagon announced at
   a press conference ("The Star", New York, Oct. 5, 1982) that contact
   between U.S. citizens and extra-terrestrials or their vehicles is
   strictly illegal.

  ACCORDING TO A LAW ALREADY ON THE BOOKS:

   (Title 14, Section 1211 of the Code of Federal Regulations, adopted on
   July 16, 1969, before the Apollo moon shots), anyone guilty of such
   contact automatically becomes a wanted criminal to be jailed for one
   year and fined $5,000. The NASA administrator is empowered to
   determine with or without a hearing that a person or object has been
   "extraterrestrially exposed" and impose an indeterminate quarantine
   under armed guard, which could not be broken even by court order.

   There is no limit placed on the number of individuals who could thus
   be arbitrarily quarantined.

   The definition of "extraterrestrial exposure" is left entirely up to
   NASA administrator, who is thus endowed with total dictatorial power
   to be exercised at his slightest caprice, which is completely contrary
   to the Constitution.

   According to Dr. Clifford, whose commanding officers have been
   assuring the public for the last 39 years that UFO's are nothing more
   than hoaxes and delusions to be dismissed with a condescending smile:
   "This is really no joke, it's a very serious matter." This legislation
   was buried in the 1,211th subsection of the 14th section of a batch of
   regulations very few members of government probably bothered to read
   in its entirety, the proverbial needle in the haystack, and was
   slipped onto the books without public debate.

   Thus from one day to the next we learn that, without having informed
   the public, in its infinite wisdom, the government of the United
   States has created a whole new criminal class: UFO contactees.

   The lame excuse offered by NASA as a sugar coating for this bitter
   pill is that extra-terrestrials might have a virus that could wipe out
   the human race. This is certainly one of the many possibilities
   inherent is such contact, but just as certainly not the only one , and
   in itself not a valid reason to make all contact illegal or to declare
   contactees criminals to be jailed and fined immediately.

   It appears the primary effect of such a law would not be to prevent
   contact, it would be to silence witnesses. If enforced, the law would
   prevent publication of contactee reports except under cover of
   anonymity, and unleash a modern inquisition in the Land of the Free.
   However, it is unenforceable, so obviously absurd and unfair that the
   public will refuse to accept it. The citizens of the United States
   will greet it with a resounding Bronx cheer and laugh it out of court,
   forcing it to be repealed.

   It should be replaced by clearly worded legislation, not open to
   interpretation in a multitude of different ways, humanely relevant to
   the contingency of E.T. contact, debated and passed by Congress openly
   instead of slipped through "under the table" without the public being
   informed.

   According to NASA spokesman Fletcher Reel, the law as it stands is not
   immediately applicable, but in case of need could quickly be made
   applicable. What this means is that it is ambiguously worded, so that
   it can be interpreted either one way or the other, as the government
   desires.

   It is certainly not a coincidence that Dr. Clifford held his press
   conference during the period when the popularity of the film E.T. was
   at its peak. As E.T. portrayed a type of extraterrestrial that was
   benevolent and lovable, the inference is that the press conference was
   intended to discourage attempts to communicate or fraternize with UFO
   occupants. However, instead of having the intended effect, it
   backfired, causing public furor. There may be some relationship
   between this fiasco and the next semi-officially endorsed attempt to
   deal with the subject of extra-terrestrials, the TV film V, which was
   featured with repeat performances and maximum publicity by major
   networks worldwide. The aliens portrayed in V are the most horrifying
   and repulsive nightmares imaginable, who are defeated thanks largely
   to a CIA hit man specializing in covert operations, the tough guy with
   the heart of gold who with the aid of the handsome hero saves the
   human race. This is obvious and transparent propaganda, designed to do
   what the government's widespread use of dis-information, and Dr.
   Clifford's press conference about the absurd lemon of a law already on
   the books failed to do: squelch attempts to communicate or fraternize
   with UFO occupants.

   One way to avoid widespread panic at the announcement of the news that
   we are under surveillance by nonhuman intelligent beings with a
   technology far more sophisticated than our own is to point out that
   this situation is nothing new, but has literally been going on for
   millennia.

   If the "flying dragons" mentioned in the I Ching intended to attack
   and destroy us, they could easily have carried out this objective long
   ago. Along with this article, the text of the E.T. Law will be
   presented. However, there are several points that I wish to make:

   1211.101 Applicability. The provisions of this part apply to all NASA
   manned and unmanned space missions...

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