One of the things that Twitter does, is allow you to display your social capital. Of course this is what Donath & dana boyd were getting at when they wrote about social networking in general, being about 'public displays of connection'.
But I think that Twitter is a somehow more nuanced display and database of one's connections than a lot of other spaces. Maybe because of the starkness of it all - just the tweets and the identifying name/icon at the side. It looks like an RSS feed.
The display of one's network is not necessarily why we get involved; but I do like to see the displays of others - just in case I want to pick out a few people to follow. How do I select?
I look for the tweets which have interesting links; or maybe I recognise a name as being someone whose work I have read elsewhere. In making selections I capitalise further on my existing networks and thus extend them - according to what I value. I can accumulate additional social capital by building on what I already have.
In my son's case, he will select according to who links to the funniest jokes; the riskiest videos; the most obscure music sites (etc.)
The reason why some people talk about hating Twitter is because they hear about twitter feeds which are populated by people (and knowledge and cultural references) that they do not value.
So. as Bourdieu says:
Social capital is the aggregate of the actual or potential resources which are linked to possession of a durable network of more or less institutionalized relationships of mutual acquaintance and recognition – or in other words, to membership in a group – which provides each of its members with the backing of the collectivity-owned capital, a ‘credential’ which entitles them to credit, in the various senses of the word.
I know that the term 'display' is a bit of an uncomfortable one - but most people do choose to keep their twitter stream public. We are increasingly happy to share what we say with many others. A lot of the time we assume our tweets will be read just by those we know - but are also aware of the potential of new followers. We display our stuff partly so that we can get to know likeminded others. (And this is why we all LURVE Web 2.0).
Just one more point before I go ... it seems strange to think about copyright and plagiarism in association with Twitter. Since what is valued is not just knowledge - but being a good sourcer of further supplies of knowledge - one necessarily credits where one got the information in the first place. If you Tweet - or ReTweet - as in quote someon'es Twitter stream, then you refer back by hyperlink to their origianal tweet. This gives you credit for picking up the source and the info, as well as crediting the originator. See copyright discussion here sourced via evestirling and digital maverick.
Can't do a post without a video ...