This question is incomplete, but I will answer it anyway in a way that you can understand.
Explanation:
A speaker has the responsibility to evaluate the sources he is using for his speech given that he is providing information, and such information cannot be wrong. Especially if the speaker is using this data to support his ideas, emphasize or clarify them, and providing false data or not checking the sources of his speech can end in his speech being ruined, since he will not be able to convince his audience or he will lose his credibility.
