Hi,
I've found a photo of a well-known US politician on pinterest.com, uploaded by Florida Ice Cream Festival. It's a simple photo with him and two other guys eating ice-creams at some venue. Can I cut him out and use him (altered a bit) for a university graphic design competition that requires I don't infringe anybody's rights?
Seeking permission from the copyright holder to use a rights-protected photograph will always be the best way to avoid any claim of copyright infringement.
There are circumstances under which a copyright-protected work, or a portion of the work, can be used without authorization of the copyright holder, however.
Under the Copyright Act, the “fair use doctrine” allows for the use of copyrighted material in connection with criticism of or comment on a work (as would be the case with reviews), in the course of news reporting (to illustrate a news story), for teaching purposes, and as part of a scholarship or research activity.
And a copyrighted work can be used as the basis for creation of a transformative work (a new work based on an existing work but transformed with new expression or meaning). A parody is an example of a transformative work.
Fair use is an affirmative defense to a claim of copyright infringement rather than permission from the copyright holder to use their work, however, so seeking permission before any use is what is wisest and advised. Getting permission is the only sure way to avoid a claim of infringement.