In the United States; hosts are considered safe from user submitted content under section 512 of the Digital Millennium Copyright Act. Storage providers, websites and ISPs (Internet Service Providers) are considered protected under 230(c)(1) of the Communications Decency Act. No cases in the US have specifically accused websites of CP. Section 230©(1) is considered a “safe harbor” but has never been tried in a court of law.
In the European union; hosts may be protected by Directive 2000/31/EC as long as they meet certain criteria.
For additional information, contact a legal professional.