I have no idea how you generated these stats. There are few dirty accounts, and even if there were more, I see no reason why detecting them should be any concern of yours.
May I remind you that this site serves for solving tasks. Users from Viet Nam (a country of over 80,000,000 population) are doing just this. If you don't like it, this is your own problem.
If you want to complain about something, you can write an e-mail to the contact address. The forum serves for building a community and mutual help, and not creating problems. Posts which do this will be deleted.
If anyone is interested in the relative activity of individual countries, stats are given below. Please consider this topic of discussion closed for good.
country numberOfUsersActiveInLast60Days numberOfDistinctIPsOfTheseUsers
POLAND 473 2994
CHINA 74 153
VIET NAM 68 432
CITIZEN OF THE WORLD 52 313
UNITED STATES 39 83
RUSSIAN FEDERATION 32 124
INDIA 31 61
GERMANY 22 261
ROMANIA 20 72
BANGLADESH 17 23
BELARUS 14 74
BRAZIL 12 20
KAZAKHSTAN 12 41
INDONESIA 11 25
CANADA 10 25
UKRAINE 9 27
SPAIN 7 29
AUSTRALIA 7 11
SWITZERLAND 7 47
UNITED KINGDOM 6 8
AFGHANISTAN 6 11
BULGARIA 6 16
PORTUGAL 5 21
NETHERLANDS 5 6
HUNGARY 4 7
NORWAY 4 4
CROATIA 4 14
AZERBAIJAN 4 14
FRANCE 4 8
FINLAND 3 3