Why there are blocks with single transaction in blockchain?

Question

Just opened blockchain.info and found two blocks with single transaction on the main page:

• 292942
• 292947

Isn't it strange? More than this, block 292941 was issued just minute before 292942 and has 128 transactions. Block 292946 was issued just minute before 292947 and has 238 transactions in it.

So the question is: why there are such empty blocks in blockchain even if there are some transactions to be included? Is this some kind of misuse?

UPD: Using this little script

for b in {292000..292999} ; do
  curl -s https://blockchain.info/block-height/$b?format=json \
    | jq -c -r '.blocks[] | "echo `date +%FT%T -d @\(.time)` \(.n_tx)"' \
    | bash
done

I found 10 empty blocks. It does not looks like a coincidence. Seems like someone thinks that this is more profitable to mine for empty block. If this is the case, it will ruin bitcoin.

Answer 1

No, it isn't any kind of abuse. You don't have to worry (well perhaps a bit) about 'transaction starvation' (i.e. transactions that get never included because miners refuse to include them), as it is unlikely that one person (or more cooperating) will obtain 51% of the hash power. And even when they obtain 51%, they will be basically cutting themselves from the potential fees involved (and huge investment is required in something that could become worthless after abusing the system, because as a result the trust in bitcoin and therefore its price will fall). Only very large organisations like governments or international banks could potentially pull such trick to bring bitcoin in discredit and recover the loss. To counter this, several solutions have been proposed, such as proof of stake (in contrast to bitcoin's proof of work).

As for why these particular blocks do not contain any transaction at all: I don't know. I don't think there is any special reason for it, but I could imagine that by chance some of these blocks have less or no transactions (don't think that's the case here) or that some independent miner simply did not bother to include any transaction because of the low fees involved.