I think what happened here is, some users have figured out that buying massive amounts of tickets increase your odds to win big amounts. They tried several times and succeeded a few times.
They might have lost more times than what they have won. We do not see the times when these users buy huge amounts of tickets and lost everything. There are also some users with HUGE referral networks... and if these users are active, they get a lot of FREE tickets for every round. { Receive 1 ticket for every roll your referrals play }
Exactly.
And for those who say that there is 5,348,264 registered users and it is impossible that some users have won 2 or 4 times I want to say NO, it is not impossible considering the number of tickets those users buy. I, for one, disabled my lottery to receive reward points instead of lottery tickets so it is no wonder that I never win in the lottery. Many others, even if they haven't disabled the lottery, never buy additional tickets, so those who buy hundreds of thousands or even millions of tickets increase their chances to win by thousands times and no wonder that they win more frequently then others.
That said, I'm not encouraging anyone to buy more lottery tickets in order to have more chances to win. Kprawn said it right: they might have lost more than what they have won, we don't know about that.
I say that. And still claim the same. Because, number of tickets is not only relevant for wining. Also there is random selection ( many users with 100 or even less tickets won some prizes. Also if you look last lottery round you have 4 users that have less then 20.000 tickets, 4 less then milion and only 2 above milion.
So lets say that only small part of all users are active. Lets say 100.000. Even with that number getting 4 rewards in last 12 rounds of lottery is nearly impossible.
That's a lot. I don't think so many users buy hundreds of thousands, let alone millions of tickets. What if there are only around 100 of such users? Then it's pretty normal that some of them win not only once.
Don't forget that the total number of the lottery tickets is always in the range from 100 million to 250 million, so we can't have 100,000 users everyone of which buys above 10,000 tickets.
Of course I may be wrong but from my perspective something like the following happens.
Around 1 million users take part in the lottery each round. 99.9% of them, or around 999,000 users, have not more than 200 tickets each because they never buy them, but they get 2 free lottery tickets for every FREE BTC roll.
0.1%, or around 1,000 users, buy additional tickets. Around 900 users buy thousands tickets each and around 100 users, or even much less, buy hundreds of thousands or millions of tickets.
Since the lottery is fair, everyone has a chance to win, no matter how many tickets they buy. That's why we can see people who had less than 1,000, and sometimes even less 100, tickets among the winners. But if you buy thousands times more tickets than others do, you chances to win increase thousands of times, so it's no wonder that your USER ID was among the winners more than once during the last 20 rounds.