Just because you can show all teh latest activity in a community doesn't mean you should.
Actually, you probably shouldn't.
Redundant activity makes the activity column redundant. If the activity column is always full of members adding each other as friends, members tweaking their profiles and writing on each other's profiles areas, we will stop looking at it.
Make sure your latest activity only shows things which can be interesting. This might include latest forum posts, latest events, new polls, open questions etc...