The issue is that certain changes - increasing your transmission power - ARE illegal and have long been illegal. The FCC is looking at putting out rules to prevent that from being possible, or at least make it much more difficult.
There are a few cases where increasing your power; as well as operating "out of band" are legal; well..actually....there is one. You can operate a 802.11 wifi device under Part 97 (amatuer radio) if you have an amateur radio license and comply with the other rules of what you can and can't use Part 97 for. There are hams using off-the-shelf WiFi with modified firmware to operate under PArt 97 rules to create wireless networks that can be used by emergency services or for other authorized Part 97 services. One example is streaming video of say...the finish line of a marathon where hams are providing some logistical services. VOIP has also been played around.
Again, you have to have a ham license to operate in this fashion; and you cannot provide a public internet connection over it; or at the very least; it must be extremely limited.