It is harder than with plain text, yes, but it can show through at times. For example, a while back I was looking through my profile settings on a forum I have an account on, and saw a "check password security" link on it. Out of curiosity, I clicked it, and was greeted with "if a Google search for [unsalted MD5 hash of your password] returns results, your password is not secure." I reported it to the site and turns out it was a leftover from their old system, and it got removed shortly after (along with the MD5 password hashes).

You could also always ask too. I was reading through the forums of another site and stumbled upon a thread of someone asking HTTPS support for the site. The staff was pretty reluctant about the idea, which made me wonder about other security concerns. Looking around a bit, I noticed that the site cookies contain a "pass" value that looks very much like an MD5 hash. I got someone who used to be staff to ask the current staff how passwords are hashed, and the answer was "salted MD5".

Also, why is my initial post getting downvoted? Generic hashing algorithms are built for speed, which is bad for passwords. Key derivation functions exist for a reason. Hell, just a while back there was a user database leak from a site called MangaTraders, and they used unsalted MD5 for password hashing. It didn't take long before the vast majority of passwords had been cracked.