You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
American_Idol

Context:
Individual contestants have generated controversy in this competition for their past actions, or for being 'ringers' planted by the producers. A number of contestants had been disqualified for various reasons, such as for having an existing contract or undisclosed criminal records, although the show had been accused of double standard for disqualifying some but not others.

Question:
Producers have been accused of planting what within the show?

ringers