online chess sorry
omline chess cheating
If it's much higher than their standard rating, that could be cause for concern, since both involve fewer constraints in the way of time and require a similar skill set. I'm not so sure about blitz/bullet though, since it involves a lot of different skills. There are stories of classical GM's who take on a random hustler sitting in some park in a blitz or rapid game, thinking they'll make a few easy bucks, only to lose!
is it true that if sombody has acrazy amount of rating points higer than blitz bullet or standard is cheating cause he ca n run his engine or use an appp to show him his best move