If the protesters only gathered and collated publicly-available facts, such as contact information, and brought the video(s?) and other facts to the attention of ASPCA and/or prosecutors, I'd hardly call it vigilantism.

That sounds to me like public-spirited citizenship, and I say "hooray".

If they went over the heads of the authorities, so to speak, and organized telephone and other harassment, then yes, that's vigilantism, and is culpable.

Dave Oesterreich