(This was written quickly and my English leaves a lot to be desired so please expect errors / typo's things not to make sense)
You're here, not because you find me interesting, because you don't, nobody does. More than likely, because you visit your super duper awesome best ever fully loaded html 5 website and there I am, the bumbling fool known as @undefined, all big and brash in the place where your tweets should be.
If that's the case then I urge you to stop and take a big breath, and go rant at some body else.
Understand the issue
You see, this problem is not my own doing, for me to put my tweets on your super duper awesome best ever full loaded html 5 website, I'd have to find your FTP, brute force the password, find the index page, save the changes, hack the server and delete the logs. It's not something I'm going to do because well, why would I want to?
A bit of a silly error as far as programming terms go and the error is technically correct, but its the handling of the error that causes the problems.
How long now?
A guy named Paul who want's my head, preferably on ice, wrote a blog post about this in 2010 that explains a bit more about this, the fact it was written 3 years show's how long this problem has been persisting. There's also some old commentary on HN about it. Hopefully Mike Spear got the message. There was a question on twitter-api about it, another one on Twitter developers forum, another one on Twitter's GetSatisfaction account
Actually one weekend, my tweets appeared on every Blogger page that used a particular widget, that goes back to 2009 so it's an old old issue.
Not just Twitter embeds
If you do a search for @undefined on twitter and view the tweets, you'll see that replies people are sending to other people are getting the incorrect username put in, again the same programming error seems to be putting my username where somebody else's username should be. These are users that have sent tweets to another user but got routed to to me, a message that never got delivered.
Hootsuite users (or the same API?)
When this problem first started, Twitter showed the platform used to send the Tweet. Then there was a common trend that the clients people where using who where experiencing this problem mostly used Hootsuite. I'm not sure if this is still true, I'm not sure if Hootsuite is the culprit or if its a component used by Hootsuite and others that are causing this but it led me to raise the problem with them, I think they looked into it but never found the issue or got distracted by cat videos.
What Have I tried to do?
Lots actually, I mean lots. I've sent many many many many many many many many many many many (I'm sorry Mr Durant, I don't know Viki) many (Yo!) tweets (and more), to all sorts of people at Twitter to try and raise the issue. I made support tickets, all of which by the way went ignored but nobody cares.
I'd really not have to read peoples mostly mundane Tweets, and most I can't even read because I don't speak 500 different languages but I can't fix this problem and seems Twitter won't fix this problem. In the end I just changed my username.
Twitter will in the end probably end up suspending my username declaring the problem fixed but its highly unlikely it won't be.
Next time you visit your super duper awesome best ever fully loaded html 5 website and find @undefined there, don't accuse me of hacking or ask me to fix it, because I can't.