Of course, it's hard to budget for next year's subscription costs when we've no idea what they are going to be! I'm reminded of the dreadful Bitcasa, a cloud storage provider like Drive, Box, etc. They charged $99/year and literally overnight announced the new pricing plan was $999/year. People had two weeks to download gigabytes of data before they would start being charged the new rate. Now, I know that YNAB would never do this, but I'm going to try and push them to offer longer pricing plans - I'd rather pay for three years up front and be guaranteed no price hikes in that time.
Securing the data using email address and password alone is just asking for trouble. You will recall when Jeffrey started publishing passwords he'd gained from the MN hack, how many of them were easily crackable like 'password123' and 'ilovemydog'. There are some measures to prevent you from choosing the ridiculously obvious ones, but as evidence of YNAB's understanding of security it's not good enough. When you register, you give them an email address but it doesn't have to be real, there's no verification step where you have to click on a link sent to that email address to confirm you authorise its use in the app. This second aspect might resolve itself once you buy a licence key, as that presumably does get emailed to you. But again, everything I'm describing is bread-and-butter security for websites holding personal data. YNAB does lock your account if it's brute forced, i.e. someone has tried to gain entry but used the wrong password. Even that in itself can be a denial of service attack if it happens too often.
So if a hacker manages to get some passwords, they can then start messing with your budget data and you might never know. Or threaten to do it, or say that they've done it to a thousand accounts when they haven't. The last thing you want in a cloud application is for your customers to stop trusting the integrity of their data.
In summary, therefore, two factor authentication is an absolute must for this kind of application. Not to mention the ability to back up your data to a separate data store.
In terms of where the data is being held, it isn't on someone's laptop in a potting shed or anything like that. They have gone with one of the biggest players in cloud hosting in the world - Amazon. But if a developer can leave his laptop open in the potting shed whilst logged in to the database, all the security in the world has just been neutralised. So that's why YNAB had a full security audit done before they went live, but so far they expect that we'll just believe them when they say they did it. Needless to say, various people on Twitter are asking for the results to be made public.
Finally of course - availability. The entire BBC domain was down for several hours yesterday, normally one of the most reliable there is. A reminder that any website can become unavailable, or you can be unable to connect to it (various Silicon Valley hipsters on the YNAB forum have been like 'who doesn't have permanent, fast access to the internet these days?' Er, most of even the Western world you muppets). So - offline data replication is an absolute must.
That said - I think if you are planning to start fresh anyway, lazycoo, it's worth having a play around with. I still don't really get how it handles pre-YNAB debt. The concept seems to have gone. But if this is really true, as I mention above, some YNABers will be permanently in the red. You can minimise any sensitive personal data by not using real names for things if you want, e.g. if you donate (as I do) to the Abortion Support Network, I'd be tempted to call it ASN. The app looks great, and has some good new features like goals. But as various people have said on Twitter, it's decidedly still a Beta, some key functionality is missing. If you're already using YNAB 4 in earnest, it might be worth sticking with it at least until they implement bank transaction import, which might make it possible to run both YNABs in parallel for a period of time, while you make sure it does everything you need.