Hi,
after the installation, a website opens and tells users that they can support the development of this addon by installing a second addon. Then you will see advertisement while surfing and thus generate revenue for the developer. However, the second addon is hosted outside of AMO. The second addon contains routines that are normally banned by Mozilla, i.e. dynamically loading JavaScript code from the developers website. Users aren’t told the implication of installing this second addon, there is no privacy policy or terms of use for this second addon. I actually had to look at the source code to find out what is does.
Is this allowed? Shouldn’t the main addon be banned from AMO? At least, this is very bad style and I don’t think this kind of addon should be allowed by Mozilla!
P.S. The addon is question is: https://addons.mozilla.org/de/firefox/addon/youtube-unblocker-plus
You can safely install the main addon, then watch the website which opens autmatically. Don’t click anything there! Instead, analyze the source code of the website and linked “support addon” to verity what’s going on. (You may use Google Translate for this website)