Re: If you don't pay the fees, you will be BLOCK.

Other day I was thinking, where goes/stay the unconfirmed transactions? It stay on the blockchain too?

Well, maybe we can stop sending btc for 24 hours, one day per year to unstuck this transactions...

And what happens if we got a flood of 1 satoshi transactions without fee?

Unconfirmed transaction are not stored in the Bitcoin blockchain.
They are temporary held in the memory pool of all Bitcoin nodes in the network.
When a miner "finds" a block and "adds" transactions into that block, they are
removed from the memory pools and written into the blockchain.

After a few days, if a tx does not enter a block, those pending txs will be automatically
dropped from the memory pool and "returned" to the original address. Then the tx will
need to be performed again with an appropriate fee.

All txs that have no fee or a very low fee, are usually ignored by a majority of nodes
in the network. During "spam attacks" most nodes are set to ignore those "attack txs".

Thanks, I was thinking that this transactions will stay there on queue forever...

So if you need to send an amount without priority and put a very small fee, it will be back to your address if not confirmed? Have a exactly "days" to this amount return or is something randon?

Technically, the bitcoins never left your address until they are confirmed within a block.
Your wallet software just reduces your amount of bitcoins for appearances and convenience.
So, it never really "returns" to your wallet, since it never left, since it only leaves when you get
into a block. So when most nodes drop your tx, your wallet makes the hidden btc reappear.

But to answer your question, my understanding is that most nodes drop old pending txs after 3 days.

Also, it is important to remember that if you underpaid a fee and want to redo the tx, you can
perform a doublespend with a higher fee and it will cause the nodes to ~~drop~~ invalidate your old tx.

This is very informative. I currently have a transaction which has been stuck for more than 36 hours. The weird thing is, I used the recommended fees of my wallet to send the coins over. Blockchain.info is saying that it is on medium priority and will confirm within 6 blocks. However, I think there has been more than 6 blocks since I sent it.

I got a few questions, I hope you can answer for me.

1. Can I cancel a pending btc transaction which has been stuck?
2. How do you double spend? Is this possible with every wallet? (I'm currently using bitwallet on ios)