Spammers will usually make it so one account opens many pages of games, effectively clogging up the real games. When spam occurs, quickjoin options become useless as the chance is very high of hitting a spammer game.
Although users cannot do anything about it by themselves, it is possible to filter out all games that have the amount of players being spammed. For example, if all spam is 6v6 games, players can filter out said games using the filter option option. This can also apply with how many turns are in the game. If spam games all use 5 turn lobbies, the player can filter out all 5 turn lobbies and effectively cancel out the spam, at the expense of not seeing games that are legitimate that use those settings.