Konqueror browser perhaps? I say that, because it appears that part of the security built into Konqueror appears to be a warning system that says exactly what you have experienced, when you attempt to go to an IP address instead of a domain name. This is because most times when you try to visit a link that is an IP address instead of a domain name, you are being presented with an IP address because it is temporary and what is at the destination is not safe. Of course, some with Firefox have seen this too.
I know. I'm not saying that EVERY time this is the case. However the makers of the Konqueror browser seem to think that the results of such occasions are negative enough of the time to post a warning when this comes up.
At least... you are not alone in experiencing this, and the common factor between you and the others who have experienced this is that they attempted to go to an IP address instead of a domain name. Not that this response you saw is limited to ONLY people who go to IP addresses instead of domain names.
In the end, without knowing the browser you are using, your OS, the address you attempted to visit, it's all guess-work in the end.