I wonder how long "commands" the Downloader can take, since if it's like infinity, someone could probably make a link to add everything to the downloader at once. It'd probably crash and burn, though. Maybe links with 10 games at once and people could just go clicky clicky with the clicky work load optimally reduced to a tenth.
Test: I don't have the downloader on this Linux computer, someone try clicking this link and tell me if it adds multiple games to the downloader. MEGA HAXORZ
If it works, I'm sure someone is bored enough to make mega links that add a lot of games, and the downloader just ignores the links to games you don't own (at least I would hope so).
/edit: bah, it adds http:// when I use that url thing. Maybe I should check this with Windows.
If that http is enough to mess it up, try copying that to the url bar. I'm curious.