Online privacy is getting a new kind of airing: In Securities & Exchange Commission filings, dot-coms are taking pages of stock-offering documents to warn that investigations, lawsuits, or legislation on privacy could clobber their investments. Take net.genesis Corp., a maker of Web-customer-profiling software. Its filing carried three different privacy-related warnings. In Be Free Inc.'s stock offering, the manager of online ads lists four different warnings. Privacy used to rate one paragraph. "No one really knows where it's going, so it's better to have people know it's an issue," says Mark H. Burnett, a securities lawyer at Testa, Hurwitz & Thibeault in Boston. The SEC says it didn't force the change. Apparently the feds declined to invade companies' privacy.