Are anarchists really allowed to exist moreso than MLs?

I'm curious about the validity of the claim that anarchism is an acceptable form of anti-status quo politics in the US because they're not actually a threat.

Is this true? Have anarchist groups not been infiltrated as often as MLs have? Is it easier to take them down?

I only ask because I feel like any form of left wing/anti-capitalist thought would be heavily suppressed here but I don't know