When down voting I usually follow the 'guideline' in the mouse-over, with the post showing no research, unclear, or not useful.
However, when searching for something, I will occasionally run across a highly upvoted question (usually due to a good answer) that, while it breaks none of these guidelines (except maybe no research), it is just a standard question that has been asked before (and sometimes clearer). I then downvote it as I don't feel it deserves that many upvotes / that much recognition.
Question: Is it considered bad practice to downvote what is considered an average question (that has been massively upvoted) to bring it down to a more 'appropriate level'?
Note: Obviously downvoting a massively upvoted question is bad, but I'm asking about ones that simply state what their problem is and that's it. No effort shown (or not said), but often short, understandable, and with a helpful answer.
Also for these, I often find even after many searches, other similar questions often encompass the problem better as a whole and have better searchability.