If you don't file a response to the complaint, you risk having default entered against you, followed by a default judgment. And, yes--chances are that the judge will likely award him what he is seeking, since you are not there to tell your side of the story and all the judge has to go with, in making his/her decision, is your brother's side. (By failing to make an appearance in the action, you are waiving all of your defenses.)
Ms. Berjis is licensed to practice law in the State of California. The laws of your jurisdiction may differ and thus this answer is for informational and educational purposes only and is not to be considered as legal advice. Since all facts are not addressed in the question, this answer could change depending on other significant and important facts. This answer in no way constitutes an attorney-client relationship.
You can ignore it... But probably it will be to your detriment. If you ignore it, your brother will probably win by default and he probably will get whatever he wants, since the judge will only hear his side. Considering the information given, it seems that you are liable, however you may have a defense as to damages. Consider consulting an attorney.
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