I have been trying to remove my content on Twitter over the past year or so. I started with deleting just my basic tweets and then followed up with deleting all my replies. I found this service - TweetDelete.net, and they do a pretty good job with the first two tasks. I did pay for the service, and it seems that since the time that I paid for the service, they have changed pricing slightly, and the plan that I was on no longer supports my next task of removing myself from the Bluebird - which is to remove my favorited tweets of others.
This has been an undertaking that I don't know how far I have progressed. I have close to 7k favorites on Twitter since I joined the service in 2007. The TweetDelete.net service I mentioned above has favorite removal, except it limits the plan I am on to just 100 a month. I believe I have found out why that is such a low number, and I think it has to do with some killswitch for allowing unfavoriting on the Twitter side of things.
I found a few scripts and extensions that will go through and unfavorite tweets for you, and ( at least in the extension's case ) it looks like a human is unfavoriting them one by one; the problem lies within the fact that it seems that when you hit a certain threshold that twitter no longer shows you the "filled in heart" to allow you to unfavorite the ones on your "liked" profile list. I don't know if this is a byproduct of some techinical change or if it is something that was planned to not allow the data to be wiped. It is rather frustrating as I don't want to give up my Twitter account completely. I still tweet about live sporting events frequently and use Twitter in that manner because it is the king of that realm and probably will be for the foreseeable future.
I downloaded my archived information, so I am going to find the IDs of the favorites and see if there is some bulk option out there on the net somewhere with those Tweet IDs. Stay tuned.
Also, yes, I know it is called X now. I still call it Twitter.