To protect yourself at the table, pay close attention to betting patterns of other players. If there are multiple cases where players clearly either squeeze you in or out of a pot with questionable holdings, you should leave the cash game table and write about your concerns to the poker site support. However, most of the time when you spot something one-off, it probably isn’t cheating or something you can do anything about – some players just play poorly and it might look like they’re colluding.