Single sentence quotations are often taken as a whole because there is no other way to review them. That's why it falls under fair use, not the partial-extract

Single sentence quotations are often taken as a whole because there is no other way to review them. That's why it falls under fair use, not the partial-extract part of it. Your example of advertising slogans is a perfect example actually. Excerpting the tweet stream does seem to be a more logical view of what's going on actually. I really doubt it would be an uphill battle.