Even Bill Gates says so. Read about that at Bill Gates quits Facebook over 'too many friends'. Here are the key exerpts:
"Microsoft co-founder Bill Gates said he was forced to give up on the social networking phenomenon Facebook after too many people wanted to be his friend.
Gates, the billionaire computer geek-turned-philanthropist who was honoured Saturday by India for his charity work, told an audience in New Delhi he had tried out Facebook but ended up with "10,000 people wanting to be my friends".
Gates, who remains Microsoft chairman, said he had trouble figuring out whether he "knew this person, did I not know this person"."
""I read a lot and some of that reading is not on a computer," he said.
Gates, who sought to drive a vision of a computer on every desk and in every home, said the information technology revolution had been "hugely beneficial" but added: "All these tools of tech waste our time if we're not careful.""
So you can use technology too much as well. Notice how he brings in costs and benefits (waste implies cost and he mentions technology as being beneficial). But the more you use something, the less beneficial it is and it can also become more costly. That is, the marginal benefit (MB) falls and the marginal cost (MC) rises. The best result is to keep adding more of something up to the point where MB = MC. I explain all of this at the following site: Allocative Efficiency. This is taken directly from notes I use in one of my lectures. Just think about friends when you read it and look at the graph. At some point, one more friend has less MB than the MC. So it means you can have too many friends because you can have too much of anything.