This was very powerful and enabled you to do very powerful keyword searches. In some ways a very different way to search. I was using this for some truly deep searches of internet sites with the content being very much from the original web. The original web being what this article is about.

Nowadays if you 'deep stalk' someone or some thing then you will find their social media posts and profile on linked in.

Back then you were far more likely to be finding them on forums or sites they created, even on those 'guest book' pages - remember them?

Alta Vista and the advanced search functionality was useful up until 2003 or so, then they became part of Yahoo! and we all know what happens when that happens. I stopped using it then but also my particular use case had gone, I was doing different work and no longer needed the search results beyond the search results, i.e. where the whole internets is bisected for the match of two or more particular search terms and their negations. Happy times, but you did have to have the skill to search like that, it was more like using the index cards in a library than browsing the shelves, a mini superuser trick we no longer have even in Google 'verbatim' searches.

What is 'LexisNexis style querying'?

I think he's referring to the ability to use boolean expressions and other more sophisticated operators. See, for reference: http://www.public.iastate.edu/~hschmidt/srch.html