EXHIBIT 23.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of our report dated March 14, 2005 relating to the financial statements, management's assessment of the effectiveness of internal control over financial reporting and the effectiveness of internal control over financial reporting of Acacia Research Corporation, which appears in Acacia Research Corporation's Annual Report on Form 10-K for the year ended December 31, 2004. We also consent to the reference to us under the heading "Experts" in such Registration Statement. PRICEWATERHOUSECOOPERS LLP Los Angeles, California August 15, 2005