On submitting an answer, the system could check if at least 75% (more or less) of the answer exactly matches either the Markdown code or the rendered text of the question or another answer, and reject such an answer with a message similar to the following:

> ###Oops! Your answer couldn't be submitted because:

> - We're sorry, but as a spam prevention mechanism, we cannot accept answers with content mostly copied from (*the question* | *another answer*).  Please add more content of your own.