Ok well first off, Hey Petco how are ya man!! ok now on to buisness. Yes they can crash the server but it also depends on the servers stability. Some servers can withstand those things but most can't. The most likely to crash the servers would be krillin's disk followd by gohan's sheild and then friezas disk. I have rarely seen a server crash from friezas disk. But I see servers crash from krillin's all the time.