Did I order this?
The advertising software typically comes bundled with a single installation program, so there is initially no way to tell what will be installed on a person's computer.
Some of the services do flag the extra software, either in the license agreement that people are theoretically supposed to read, in a separate "readme" text file, or as part of the installation process. It's rarely entirely clear what the software does, however.
One of the most pervasive pieces of piggyback software is dubbed "SaveNow," created by a company called WhenU.com. Distributed along with BearShare, iMesh and the Global DivX player that allows people to watch many online movies, it tracks where a person goes online and then pops up separate browser windows with targeted advertisements or special offers.
Unlike some "spyware" software, this one doesn't send information back to the company that created it. But it continuously downloads updated information about new offers and keeps a record of where a person surfs on that person's own computer. It runs continually--even when the program it came with is not operating.
Another similar program is distributed with Audio Galaxy. Created by a company called Gator, the "Offer Companion" is slowly downloaded to a person's computer after Audio Galaxy is installed and eventually starts sending information such as e-mail addresses and Web surfing habits back to Gator.com. It also pops up advertisements as people surf.
This is an optional feature with Audio Galaxy. People who don't want it must pay close attention when first installing the service, or the ad software will be downloaded automatically.
The advertising software has prompted some discussion on bulletin boards online and drawn criticism from people who say the extra programs are privacy violations and can hurt computer performance.
"SaveNow is buggy and tends to screw up your network connection," Manish Vij, a BearShare user and founder of Web design firm NetStudio, wrote in an e-mail to News.com. "Every time I launch a browser, SaveNow keeps trying to run and makes my network connection flaky."
People can check what kinds of software might be running in the background without their knowledge by checking the Windows Task Manager, which is started by pushing the Alt, Tab and Ctrl keys all together. More information on other piggyback programs can be found several places online, including Cexx.org.
Privacy experts caution that people should be aware of what they are downloading and where it is from, particularly if it is a piece of software. They say companies need to do a better job of warning their customers what will be installed on their computers.
"I think this really breeds mistrust across the industry," the Privacy Foundation's Smith said. "I think companies need to be more forthcoming."
