Scraping for research and/or personal use should always be legal.
Even if the burden put on the scraped website is far from "fair"? At my last job we had half the server capacity used by scraping bots most of the time, despite blocking Tor (since it was used exclusively for scraping most of the time). Such use translates into real operating costs just for being scraped, depending on your way of monetizing with 0 (no ad views) or negative income from those "users" on top (sometimes it's the competition or agencies selling your data so people don't have to use your website).
And it is your right to sue whoever resells your data without licensing it.
But a legal pursuit just for scraping per se looks mean to me.
For instance on LinkedIn, how many of the 400M strivers do I really want to network with? Yet I (or my bot) can see them all.
Imagine a world where you don't have to re-enter your education and work history for every job you apply to! Imagine not having to create a new resume every time you decide to switch jobs! Imagine just sharing a semi-private URL instead.
This sounds like a market prime for disruption.
Scrapebox does exactly that http://www.scrapebox.com/google-cache-extractor