Be it radio, TV, cell phones or internet, the person who starts using them ends up wasting a lot of time on them. Using them as per necessity is of course fine, but using them without any purpose leads to other harms among whom wastage of time is a major one. There is a Hadith in Sahih Bukhari:
Translation: It has been narrated on the authority of Hadhrat ‘Abdullah Bin ‘Abbas (May Allah be well pleased with them) that the Holy Prophet (Sallallahu alaihi wa sallam) said: There are 2 bounties of Allah about whom most people remain heedless, one is health and the other is leisure. (Sahih Bukhari, Hadith No. 6412; Zujajatul Masabeeh, Vol. 4, Pg. No. 148)
The word “Maghboon” mentioned in the Hadith has been described to have 2 meanings. One is that about these two things most people are in loss and are not drawing benefit from them as they should. They waste their invaluable time and end up suffering losses. The second meaning is that most people are heedless about those two bounties of Allah. They don’t realize that these 2 things are in fact bounties of Allah. That’s why they spend their time doing useless things.