US Citizens are allowed to hear opinions of others when engaging in political discussion. That's why it's called a discussion. If you "protect" them, because the opinion they are hearing might be from a boilerroom overseas or more likely, a DNC or RNC funded organization here in the US, you are almost certainly going to swing the pendulum too far and end up doing far more destruction to the democratic process than those you started off "protecting" us from.
Look at Facebook's use of snopes.com as their "fact checkers". We now know that snopes.com is extremely politically biased.
People who say they are protecting you from something are usually victimizing you instead. Please don't protect me.