Of course there are! And it's all part of SV culture.
A few years ago I tried to sign up to LinkedIn only to find out I already have an account. But it was not my account - it was someone else's, who has a similar name (and apparently thought my email address was his? I don't know...). I could reset the password and log in to his account. I was a bit scared when I contacted LinkedIn support, because I was worried they would accuse me of hacking. Eventually they disconnected my email from his account.
Now, I know that LinkedIn isn't a SaaS platform, but you would think that such a big company wouldn't make such rookie mistakes. Even if they launched without email confirmation, and added it later, there should be some mechanism to "fix" the old accounts.
I think it's especially common for mobile apps to accept emails without validation: I have a couple of accounts for different people with similar names on my rarely used gmail email.
A few years ago I tried to sign up to LinkedIn only to find out I already have an account. But it was not my account - it was someone else's, who has a similar name (and apparently thought my email address was his? I don't know...). I could reset the password and log in to his account. I was a bit scared when I contacted LinkedIn support, because I was worried they would accuse me of hacking. Eventually they disconnected my email from his account.
Now, I know that LinkedIn isn't a SaaS platform, but you would think that such a big company wouldn't make such rookie mistakes. Even if they launched without email confirmation, and added it later, there should be some mechanism to "fix" the old accounts.