I would like to suggest that the answer to the question varies with the context within which the construction of the list occurs. For example, in an employment or in an educational environment, it appears to me to be quite ethical to define participation in a list (as a primary means of intra-organization communication) as a criteria of participation in the larger organization. In that situation I believe it to be quite acceptable to construct the membership of the list as a routine IT function.
However, I believe it to be unethical to use search engines or other techniques to compile files of e-mail addresses and to then add them to e-mail lists without the prior consent of the owner. Current practice of creating such lists with an "opt-out" provision (wherein the recipient is advised to reply to a given address in order to be removed from the list) is simply unacceptable.
As an example, I recently found six identical messages from a political advocacy group that I personally find repugnant and offensive. The messages notified me that their research suggested I would be sympathetic to their cause, and solicited financial and professional support. The ISP that provided me with that particular e-mail address uses an alias system, such that my responses to the organization appeared to come from a slightly different e-mail account. I was bombarded with additional communications before I was finally able to persuade them I found their mailings offensive and did not wish to participate.
I apply the same criteria to commercial solicitations. Participation in such lists should result ONLY from the conscious decision of the recipient to join the list.
The practice of adding addresses to lists without permission is unethical to me. But it also in the overall scheme of things a small matter, as in taking a few paper clips from your employer. An implicit issue is what assumption persons make about the amount of privacy possible on the Internet. I assume virtually nothing I send is completely private and behave accordingly. Others who have less conservative assumptions may be more at risk.
I'd like to comment. Although many general principles may apply in this discussion, I find that, personally, my reaction to unsolicited e-mail depends almost entirely on its content. I never regret receiving genuinely useful information or information from close friends or family. I am must less forgiving of e-mail that clearly serves none of my interests. I am deeply offended by e-mail (such as racism or pornography) that compromises my personal values. Thus, I am generally not opposed to being contacted at will by friends and family; I think unsolicited commercial e-mail should be limited (only very short messages or only a very few a day); and I think personally offensive unsolicited e-mail should be prohibited altogether.
Last updated April 17th, 2003.