Anonymous Sources - Phil's Rambling Rants
I agree with the principle that no one's actions should be limited except to prevent harm to someone else, but that's not really the issue here. Not testifying does bring harm, to society as a whole if a guilty person goes unpunished, and possibly more immediately to their next victim. In some cases, the harm of not testifying may be very great indeed; society as a whole may be clearly better off with the testimony. But testifying can bring very definite harm too, if the person who is hurt by their testimony, or their friends, retaliate, and the retaliation affects the testifier much more personally.
I am struck by the thought that refusing to testify is a lot like paying ransom to a kidnapper. It seeks to selfishly protect one's own interests at the expense of enabling much greater harm to anonymous others in the future. I find this disturbing, because I'm pretty firmly convinced that paying ransom should carry the same punishment as kidnapping, but I'm much less convinced that it's fair to sanction someone for not testifying against the mob when they have good reason to believe that they or their family will be killed for it. I think I'm being inconsistent, but I can't work out a good excuse for it.