Yes, but it's generally only used to add information that doesn't have any particular impact on the end user. For example, with product names, post titles etc people would expect it to generally be some sort of abbreviated version and there isn't much issue if it doesn't match what's served on the page. The problem here is that to a user the URL indicates the identity of the @author and they may not notice that the @author is slightly different when they view the tweet itself which has (theoretical, at least) security and privacy implications. Particularly if exploited in such a way as to encourage a user to follow a link (or open an image or other content) that they might not follow if they did not believe it had come from a trusted user.