The re-tweet is one of the backbones of the Twitter system and it plays a significant part in making links, and the sites and articles that they lead to, go ‘viral’. The ripple effect of a message getting re-tweeted throughout the network is a beautiful thing to see, and if you’re the recipient of all that resulting traffic, a reason for some celebration.
However, you have to be careful. I’m not a subscriber to the notion that suggests it’s poor etiquette to alter the existing prose when doing a re-tweet, but I do think you have to make distinctions between what the original poster (OP) said, and anything you have added yourself.
On several occasions I’ve seen things that I’ve never actually said ‘re-tweeted’ in my name, simply because the re-tweeter changed all the words but left the RT @Sheamus part alone. Often this is an accident on their part, and it can end up with amusing consequences.
Or far more severe ones; like the @reply, you could do a lot of damage to a person’s reputation with a series of re-tweets if you intentionally set out to make an individual ‘say’ things that they never did. Not only does this bad information go out to everybody in your network but, perhaps ironically, thanks to further re-tweets, it has the potential to quickly spread to millions of people.
RT @KarlRove I was rooting for Obama all the way!
This is why I use and recommended the via tag over the RT. For me – and I accept this might be a personal view – the RT should, for the most part, be a literal re-posting of the original message. If you tamper with it, I think you need to do everything you can to ensure that your words are clearly separate from the OP’s. More often than not the RT @Username part comes first, right at the beginning of the message, and I think that the words that follow are seen by the majority as coming from that user.