Im wondering how should I admin my own forum where members posts "related" but copied text from different places on the web. Should I start banning members ? How do you handle this yourself ?
I don't think they should be banned without some warnings. Some people don't realize that it is wrong. Here is an example here from yesterday http://forums.digitalpoint.com/showthread.php?t=1197459 where someone posted someone else's work without permission or acknowledgment.
I understand in your example that someone dont realise it's wrong. But on my site they copy a text related with the topic just to have something to post about while having their link in their signature. Also when I look the post in copyscape they have done the exact copy on a handful of sites. In my example I have a feeling they dont care.