I try to differentiate quoted material from my own by either changing text color or using the quote box or both. I add a link, sometimes twice.
I do as much as I can to ensure the reader doesn't mistake someone else's work for my own. Sometimes it still doesn't work.
If I'm quoting segments I'll either put them in separate quote boxes or use the " ... " symbol to denote there was unposted text between the blocks of text I quoted.
While I try to be scrupulous for myself, I don't necessarily expect others to do the same -- as long as I can differentiate the two, which typically hasn't been a problem for me.