This is a very valuable addon that I recommend using. It catches a lot of duplicate accounts.
However, after it catches possible duplicates, you need to take a lot of time to compare accounts to see if it really concerns a the same person. This addon does not report on important match factors which ties accounts together. Every day of the year I have to spend a LOT of time on this while 90% can just be automated.
The last update was January 2016. I had expected a yearly feature release for an addon which costs 48 + BFO.
Meanwhile browsers have implemented many privacy features which reduces the effectiveness of this addon.
This would have been a 5 star review if the above was addressed.
This add-on is worthless and TBH I feel stupid for having purchased it. It doesn't catch almost anyone, except constantly registering me as a dupe account whenever I use the "login as user" add-on (which I can't really fault the author for). But the original multiple account detector catches 5 for every 1 this add-on does (checked for false positives), and I've given it ample time to have planted cookies, etc., on the current users that are being caught. Honestly a waste of money, will not be renewing my license. Disappointed. :(
I run a writing/roleplaying site where users are allowed to share written works and play games together like Dungeons & Dragons. One of the biggest issues we is enforcing the no Erotica rule because people keep coming back and doing it and getting past bans. I prayed to the Internet Gods for a long time and wmtech answered and delivered. Seriously thank you, very much worth the price.
After having this installed for two days, it has already payed for itself! I have a large site that is prone to multiple accounts problems due to our topic and our policies. Previously I was using a free addon, which worked well for flagging people but was not designed for a huge member base and was a mess to go through the logs.
What I love is that it only flags each alt account once. It lists all the alt accounts right there in the post, along with their email address, their post count, likes, warning points and registration date. I've been able to spot many true duplicate accounts vs a shared machine at a quick glance because of this.
Should this addon continue to get great support, this is more than worth the purchase price if your site suffers from multiple account issues!