Obscenity laws are a tool used by the government to regulate our rights to freedom of speech. Anything considered obscene can be prosecuted by the law as a method to bypass freedom of speech rights. Primarily the Miler Test is used as the basis to charge, persecute and oppress:
"Whether "the average person, applying contemporary community standards", would find that the work, taken as a whole, appeals to the prurient interest,
Whether the work depicts/describes, in a patently offensive way, sexual conduct specifically defined by applicable state law,
Whether the work, taken as a whole, lacks serious literary, artistic, political or scientific value."
It is intentionally vague and can be used by any group to oppress a person from even going as far as expressing creative thought.