Here's my view:
Prior to the Facebook/Twitter addition, people were free to link to comments and/or posts on my journal to begin with. Locked posts could be linked as well, but people had to be a friend to see it or people would have to copy/paste the content. I also have very, very few locked posts. The majority of my journal is fic, art and other misc. crap. People could easily paste a link in Twitter to something of mine or a link in Facebook to something of mine and I was none the wiser. Now I can be wiser and with ping back see where people are linking my things like they've probably been doing before.
I'm NOT connecting my Facebook account to LJ since FB is 'real me' and LJ is 'fanfic' me. By not connecting to FB, what's the worse that can happen? Some random person browsing my LJ shares a link on their FB/T page that links all their FB/T friends back to my LJ. Will those people know who real me is via FB? No. Is it any different than people coming to my LJ from Google searches, ficfinder comms, crack_van or any other non-LJ list of favorites and the like? Not that I can tell. The only difference is, they just made it easier to do something that was already possible to do before.
I already track something like ping backs from my fic website that allows me to see if/where people hotlink any of my fanart/pictures on a different site as well as where people come from to view stuff on my site. It's kind of fun to track actually. A while back, I found a small group of people on some random forum praising my fanart and it made me excited. It was like finding a stash of missing positive reviews you didn't know you had.
I guess that's my take on it. *shrugs* Even if it doesn't match everyone else's.
ETA: Since I don't use Twitter even though I have a fanfic me Twitter account, I won't be crossposting there and since I will not connect to FB, I won't be crossposting there. I'm already terrible about updating my DW account and crossposting to here from there...
PS: This evening I will do an update post on the fire with more pictures. My parents are hanging in there and the one cat (Callie) is doing quite well and my parents have taken her to my grandma's house where they are staying for the time being.