“Everyone was doing it” has never once gotten anyone out of anything.

Group participation feels like it distributes responsibility, and it does not. Standing in a crowd changes how a decision feels while you are making it, lowering the apparent risk and the apparent weight, but the accounting afterward is always individual. Nobody has ever been excused on the grounds that the room agreed.

When a plan is gathering momentum, ask what you would think of it alone. If you would not do it by yourself, the presence of other people has not made it a better idea.