I realised that I had a problem straight after Yom Kippur went out. I had spent the last two hours of the fast with a splitting headache and was desperate for something to eat. So, as soon as the clock struck 19.37, I ran to the kitchen - to find my mobile phone and check my email. After 25 hours, supper could wait.

It's the same story after Shabbat, when my Facebook status is updated even before my husband walks home from shul, just five minutes away. If I wake up during the night, I quickly read my latest messages. I can't even watch television without a computer on my lap. It's an addiction.

My Rosh Hashanah resolution for this year, then, is to spend less time on my computer and mobile - and in fact to banish them altogether while my young children are awake. I fear that my constant need to nip online is becoming unhealthy. All too often, when my children come home from school, they do not have my full attention because I have my mobile phone in one hand. I am also quite sure that the concentration issues experts identify in modern children, and which are often blamed on television, are true for me as well. I don't seem to be able to write more than a few lines on Microsoft Word without flipping back to the internet. It's almost involuntary.

A quick Google search (don't worry, the children are asleep while I write this) shows that I am far from the only person worried about internet compulsion.

So why is this a Jewish issue?

First, because understanding the magnitude of my reliance on the internet has made me genuinely grateful for Shabbat, an entire day on which electronic communication is forbidden and family time enforced.

For 25 hours, without the constant "buzz" of social networking, I am able to concentrate on the people around me, on books, on spirituality - and to think more clearly.

Far from modernity making Shabbat archaic, the notion of a day of rest, including from all technology, becomes ever more relevant as the gadgets get more sophisticated. Without the force of divine law, I am quite certain that nothing - certainly not my own willpower - would tear me away from my computer for that long. (For some Orthodox teens, even halachah and the strongest social taboos are not enough; as I wrote in my column last year, there is an American trend of "frum" kids texting on Shabbat, while claiming to be otherwise fully Shabbat-observant. They call it "half Shabbos".)

Second, it is all too easy to laugh at the Charedi rabbis for being scared of the internet, as shown in their repeated calls to ban internet-enabled phones, and in the recent mass rallies, in London and New York, against the evils of the world wide web. But they do have a point: the internet can be dangerous.

For the Charedim, the danger lies in the content. The rabbis are afraid that their followers - who have been getting internet for years - will have access to knowledge, both Jewish and secular, and to other people, that could subvert their own authority. Ultimately, they are scared the net will undermine their social structure. (A good thing, I say.)

The danger for me, and I believe for many others, is in the internet's compulsive nature. It doesn't even matter what I'm looking at, it's the fact that I'm looking the entire time. I'm scared that it can undermine my family life - and me.

Most of us accept that we must be selective about what we read online. But it's time to be far more conscious of how much we read and when. And if by next year I can't pass the post-Yom Kippur litmus test, I will be swapping my precious iPhone for a non-internet-enabled, rabbinically approved, entirely kosher handset.