EBay Inc. has begun monitoring items for sale on its site for possible copyright infringement in response to pressure from software makers and intellectual property interests. The new program has removed about 12 listings per day for software, movies, music and other copyrighted content since it began in December. The software industry's anti-piracy trade group and manufacturers of copyright products, such as Microsoft Corp., pushed for the change. The program is staffed by 15 full-time employees. For software sales alone, the company has two full-time lawyers devoted to fraud prevention, as well as a software-industry liaison and a special e-mail queue for industry complaints.