Tugging on Superman's Cape

Similar to "riding someone's coattails," to be "tugging on Superman's cape" is to be along for the ride, benefiting from the work of others for one's own separate, unearned benefit. Ex.: Spammers trying to take advantage of the wonderful followers of the Facebook page, English Idioms. These people are attempting to "tug on Superman's cape" and profit purely by taking advantage of others. Shame on them.