It was using extra CPU cycles, but it was transmitting it over the Internet to a central server. As a result slowing down the bandwidth of other tasks over the Internet and possibly the local Intranet. Bandwidth theft sounds like the issue here. If so, better ditch those SETI programs.
My employer has a polciy against instant messenging and chat programs on the networked workstations. Also other programs, such as Real Networks Real Player are banned (Non-Licenced and Real Player sends information back to Real Networks so it scares the crap out of the PHBs so they banned it).