Many people using AuthenTec's fingerprint readers with the TrueSuite software had a very nice surprise from Apple when they upgraded to OS X 10.9... After the update it was impossible to login!
Seriously?! Apple freaking owns the company and they didn't even consider this?! Outstanding job! 
There do is a workaround which allows you to bypass the login screen to uninstall TrueSuite, gaining back access to your account, but personally I opted for a clean install, hoping to avoid further problems.
Anyway, once this problem is solved, one question remains...
What are we supposed to do with our AuthenTec fingerprint readers?
I've got two Eikon readers, one of which I bought 2 months ago, are them completely worthless now? Since Apple bought the company their website vanished, and no one knows if there is going to be any type of support for these readers... I'm not asking for new features, I just want to be able to use them like I did on OS X 10.8, it shouldn't take much work and it doesn't seem an unreasonable request to me...
Anyone in the same boat?
There do is a workaround which allows you to bypass the login screen to uninstall TrueSuite, gaining back access to your account, but personally I opted for a clean install, hoping to avoid further problems.
Anyway, once this problem is solved, one question remains...
What are we supposed to do with our AuthenTec fingerprint readers?
I've got two Eikon readers, one of which I bought 2 months ago, are them completely worthless now? Since Apple bought the company their website vanished, and no one knows if there is going to be any type of support for these readers... I'm not asking for new features, I just want to be able to use them like I did on OS X 10.8, it shouldn't take much work and it doesn't seem an unreasonable request to me...
Anyone in the same boat?