Copyrights is "the exclusive legal right to reproduce, publish, sell, or distribute the matter and form of something (such as a literary, musical, or artistic work."

Source: Merriam-Webster Dictionary

Responsible use of information means that 

• We should always for any notification for copyrights of whatever we have found on the internet and 

• We should assume that it is automatically protected by the intellectual property laws if we do not see any copyrights notification