I welcome the Windows users in this party!
Nothing stops you from saving the keys and mnemonic seeds and then getting control of those wallets. I would never use an online mnemonic seed generator like this one. Looks very suspicious, even though the pool looks ok. Just remember who many millions were stolen the same way with an online IOTA mnemonic seed generator.
Yeah, SondysIT saving all generated wallets, then one by one trying synchronized (take a long time) and search for some coins

You can look into source code, there is no XHR request or anything else which allows him to view what you do. U can save whole page [
http://bitnotepool.ga/pages/support.html ] to your computer, switch off from network and generate own address. Then nobody can acces to it

He did it because win wallet is not released yet. But I understand your concern.