<What do you think about players like joking, who are artificially creating high ratings using multiple accounts? This one is a special case though, because he is also a pretty good player (five in line).
But what he does really [edited] more and more. Just look at it: there were created accounts like renjuplayer, niicegiirll; perhaps others used to collect rating points from various opponents, and transferring rating renjuplayer -> niicegiirll occassionally. Then there were created target accounts like joking and blade2004.
Those pick mostly weaker opponents or opponents tested before and again transfer rating renjuplayer, niicegiirll -> joking, blade2004.
I think their rating should be reset and they should be allowed to gain it by fair play rather.
Of course, this is perhaps thought for a start, perhaps he plans to play strong opponents further and this he only uses to get good starting position.

If you dont believe, just watch their game times when they "played together".
And watch their login times by adding them to friends or looking to database.
As most of the accounts log in pretty close together, its pretty clear to see.
Measures to prevent such cheating behaviour are hard to create...
Perhaps players with same IP address shouldnt be allowed to play together.
Of course IP can be framed, but at least they will see they need to put more effort
into it, and they will never forget they are really cheating.
Or people should report such abuses when they spot it, and warn opponents of such
players they are only helping someone to create rating base.

Such behaviour might cause some players to lose appetite of playing.

Excuse, if I cause some bad atmosphere but I cannot keep it for myself any longer.