In sustainability studies the 'rebound effect' explains why people use clean devices such as smart heating longer – it is economical and clean so leaving it on won't hurt. As a result, one could end up using the same amount of energy as with your old, inefficient heating. But also in 5G, the rebound effect is expected to occur – both in ways related to sustainability and 'smartness'. Should we throw ourselves enthusiastically into 5G, without thinking about how we use our internet connections in the future? A mini essay by Socrates Schouten (in Dutch).