There is great skill in being a good follower. On really steep or technical terrain it becomes nearly impossible but the rest of the time you'll see that doing it well is really quite difficult. When following closely, always keep a finger or two on your brake levers. Mountain biking is an inherently dangerous sport. We all know that.
Safety is cumulative.
It is your responsibility not to be the cause of an increase in that danger for your fellow riders. Do not go around blind turns with excessive speed. And don't ever, ever tailgate. Don't even come close. If you can ride faster, then go first if you want, or force yourself to hold back.