Students and scholars holding F-1 or J-1 status have a number of opportunities for employment to supplement their classroom experience and personal funds. In every case, you must have authorization to work and you must follow whatever conditions apply. Working without work authorization, working too many hours, or violating any condition of your employment permission results in loss of status.
Definition of “Employment”
“Employment” is any type of work performed or services provided in exchange for money, tuition, fees, books, supplies, room, food or any other benefit. If you receive no pay or other benefit for work performed this activity may still be defined as 'employment'.
Please check with your international student advisor to confirm whether or not your internship might be considered employment.
http://www.ice.gov/sevis/employment/ - ICE guidelines on both on campus employment and off campus employment.
http://www.law.cornell.edu/cfr/text/29/553.101 - US Government regulations defining a ‘volunteer' as opposed to ‘employment'
http://www.klaskolaw.com/library/files/murky_f-1_employment_questions.pdf - Outlines some of the specific challenges when defining ‘employment' for F-1