(I'm assuming you mean Prosper 202 when you say hosted)
It means that you are not using an SSL Certificate on the domain you installed 202 onto, as a result the connection between your browser and the web server is not encrypted. So many browsers will warn you when entering a password that a site is 'untrusted' or 'insecure' because it is *possible* for someone to snoop your connection between the browser and your domain especially on a wifi network to grab your login details.
If it's important to you, you can get an SSL Certificate for as cheap as 10$ a year at NameCheap, once installed you can then log into your account at an http:// style url, which will encrypt your browser's communication to either 128 or 256kbit, thus reducing the potential snooping of your traffic.