The Asilomar Conference on Recombinant DNA was held in 1975 and its purpose was to establish guidelines for safely working with new recombinant DNA technology. The need for such a conference was instigated in 1974 by the construction of a bacterial plasmid that was deemed potentially hazardous. This plasmid contained elements from the monkey virus, SV40, which had been shown to cause cancer in mice. The idea of transforming this plasmid into a bacterium caused enough concern that a worldwide moratorium on recombinant DNA technology was called for by American scientists. The goal of the Asilomar Conference was to establish the conditions under which research in this area could continue. Many recommendations for experimental protocols were agreed upon. Additionally, three kinds of experiments were to be deferred until a later date. These experiments that were deemed too risky were cloning of genes from highly pathogenic organisms, cloning of toxic genes, and large scale production of gene products harmful to humans, plants or animals. Some of these kinds of experiments are now done routinely, and I do not know if there was ever a consensus of when it was determined these experiments were safe.
By taking initiative, the Asilomar Conference avoided potential governmental or other regulatory involvement that may have severely limited recombinant DNA technology in the long term. Instead, a timely relaxation of the guidelines, as knowledge about the true risks of these experiments accumulated, was a perfect fit for scientific progress.
Interestingly, I have spoken with scientists who were doing recombinant DNA research at the time who said that, in reality, the moratorium was not observed. Research continued in the field as it was an exciting and competitive time. I was also told during this time recombinant plasmids were exchanged between researchers by drying them on paper and mailing them, a practice still done occasionally today.
While there are some definite differences between these two calls for halting research, the current call for a moratorium on avian flu virus research has similar goals as the moratorium on recombinant DNA research. I think it would be a success if it had similar outcomes to the Asilomar Conference.
Certainly the moratorium has different goals than the censorship of two recent H5N1 papers, which is directed at stopping the dissemination of information about specific transmission determinants of H5N1. I have read a couple of articles that seem to get confused about the goals of this censorship and the goals of the recent moratorium. Indeed the current call for a moratorium doesn't mention the word terrorism or suggest censorship as a security measure.