I'm sick of this conversation and people who try to justify that it's ok. Pack searching is stealing from other hobbyists, plain and simple. Etiquette is the correct word. Morality is another. Pack searching is not a job or hobby, though some losers treat it as such. You wouldn't do it at a Hobby shop or card show because your likely to get embarrassed. Though i've heard stories about those who have tried.
Retail is the exact same thing IMO. The only reason it continues to happen is because retail stores are still selling the product. Without a hobbyist like you see at a show or LCS watching, retail stores are raped over and over. Some people steal as a hobby too, it doesn't make it right at any age. Sorry for my rant, but I do not like pack searchers.