At present my code reads a tweet in plain text format. It then adds <a> tags to any links, the @username and the #tags. It then looks for twitpic/flickr/youtube etc urls it will add a clickable thumbnail to the top of the tweet. As I can see it, my code will need to put the t.co in the <a> tag, do a lookup on the full url and replace the t.co in the text of the tweet, check for twitpic links, add the thumbnail, BUT ensure that the link on the thumbnail goes via t.co else it will be a breach of the TOS. Will not parsing the image url and displaying the thumbnail in the first place be a breach of the TOS as I haven't sent the users browser via t.co?