Waste
Computer equipment develops so fast that it is hard to keep up with the times. Each year vast quantities of it are turned into junk, either by developments that render them obsolete, or mishaps that leave them beyond economic repair. Either way, they become worthless, and are treated accordingly - which is to say that they are simply thrown away.
In environmental terms, this is a disaster in the making. Computer hardware contains all kind of nasty substances, including lead, mercury and cadmium, and we are buying more and more of it every year. Where is it all going to end up?
One thing we can do is use computer equipment longer. Mac users already do this - Macs have a far longer useful working life than Windows PCs - and the advent of Linux has provided a new lease of life for many old PCs. But ways need to be found of making good use of older equipment for much longer. Manufacturers need to make computers that are easier and cheaper to repair, and to make them of less environmentally-damaging materials. If we're going to treat them like consumable items, then they'll have to be made of more safely-disposable materials.
At any rate, we face a strong obligation to use more carefully and throw away less. That we throw away computer equipment which works, or which can be repaired, is a disgrace. The LEGO Mac is one small example of an alternative to throwing things away.