It could become a problem if a USB hub is connected to the port that is powering multiple devices as it could mean that this exceeds the maximum power that can be supplied by the port. This could result in connection problems and even data loss.

A good start is to find out how much power the USB devices need before connecting them together to an USB hub. The free portable software USBDeview by Nirsoft can do that. Just download the software, unpack it and start it on the target computer system.

Power is one of the information provided by the application. You need to scroll a bit until you find the column as it is located near the end.

You need to click on the Power column title to sort the devices. Not every device requires power and this brings those that do to the top of the list. It is not always that easy to identify devices. The description and drive letter usually help out here. You can also try and disconnect devices and refresh the listing to identify it by looking at which device is missing from the listing after the disconnection.

Did you ever run into troubles running multiple USB devices on one USB port?

USB Blocker (via Techie Buzz) is a software program that can protect USB ports from being accessed unauthorized. One main benefit of USB Blocker is that it relies solely on group policy mechanisms and does not have to be deployed on client computer systems. USB port protection can be achieved with just a few mouse clicks on connected computer systems.

The application is controlled via a small interface that pops up for the first time after installation. A click on the Block USB Devices checkbox enables the options for managed active directory domains and provides the means to exclude computers from being blocked by the USB port protection software. There is also an option to only block devices for specific organizational units in the Active directory.

The usb port protection software can only be downloaded after a quick registration (without verification) at the website of the developer. USB Blocker is compatible with most Microsoft operating systems. A commercial version exists as well which extends the functionality of the USB port protection to include additional devices among other things.