HP wants you to print things through its cloud service, wherein you pay a subscription fee for ink and your usage is routed through its servers. To encourage you to do this, it covers the USB port on one model with a sticker with a No Smoking-style "No USB" logo on it–lest you simply plug in your printer and start printing things with it before you've endured the hard sell via network setup.
The sticker also has a WiFi symbol on it, a useful hint. One user claims that if you don't do network setup, the printer will brick after printing a 20 pages, until you do so.
Don't buy a HP printer. They're no better than the competition even if you're the happiest cloud consumer they ever lucked into. Get an old Brother laser printer unless you need to do photo/art prints, in which case get Epson.