The most serious concerns with visiting (or using) a website that doesn’t have SSL / HTTPS are all about security, privacy, and fraud.

Here are the big ones:

1) Password and account theft

If you log in on a non-HTTPS site, attackers can capture:

your username + password

session cookies (which can let them “be you” without even knowing your password)

This can lead to full account takeover.

2) Identity theft

Even if you don’t enter a password, attackers can steal personal data like:

full name

email address

phone number

home address

messages you send in forms

That info can be used for scams, impersonation, or identity fraud.

3) Credit card / payment theft

If payments are done over HTTP (no SSL), it’s extremely dangerous:

card numbers can be intercepted

billing info can be stolen

purchases can be altered

4) “Man-in-the-middle” attacks (MITM)

This is one of the biggest threats: someone sits between you and the website and can:

read everything

change anything

redirect you somewhere else

This is especially common on public Wi-Fi.

5) Malware injection

Attackers can inject malicious scripts into the site traffic, which can:

infect your device

steal saved browser data

install spyware/adware

hijack your browser

6) Phishing and fake pages

Without HTTPS protections, attackers can manipulate pages to show:

fake login screens

fake payment forms

fake “update your account” prompts

This tricks users into giving away sensitive info.

✅ In short: The serious concerns are stolen logins, stolen personal info, stolen payment data, and malware/phishing attacks—because without SSL, your connection can be watched or modified.