Yes. Remember people! XEL using brainwallet. If you setup node on Linux/Mac/Windows or if you launch Desktop app on Linus/Mac/Windows and you provide passphrase "test" you'll get access to the same wallet. So if you used passphrase "test" and someone else on the world used same passphrase you both get access to the same account (so your funds may be stolen!). That's why you must choose a GOOD passphrase. If you don't have idea how to create a good one use "Create account" option. It will generate for you 12 english words AND THIS IS YOUR SECRET PASSPHRASE to access your account from any node/desktop client on the world! So keep it in some safe place and don't lose it.

Example:

User A from USA used weak, unsecure passphrase: "test". Account for this passhprase has address: XEL-E8JD-FHKJ-CQ9H-5KGMQ (you can check this in your node/desktop client and here https://wallet.elasticexplorer.org, just type same passphrase in both those places and you'll see you have access to this address)

User B from China is a hacker, he scans (with bot most likely) weak accounts all the time to find out if some other users used weak passphrase. He finds out that User A just transfered XEL to account with "test" passphrase so he take those funds to address he controls.

In XEL, your private key is generated from your passphrase. If you use weak passphrase you will most likely lose your XEL.

If you need some Bitcoin world simple analogy take a look at Electrum. Your wallet is generated using 12 words. You can then recover your BTC wallet if you have those 12 words.