Here's a little story about a well-meaning guitarist with some new toys:

I'm the "sub" for my friends' classic rock cover band and I go to their practices each week to hang out and get the tunes in my head.  The regular drummer keeps his kit in the guitarists (very large RV garage) with the rest of the PA equipment.  

The guitarist bought a bunch of mic's and some additional speakers so he could mic the drums.  That's fantastic!  But there's a catch.

First, he clipped these rather large mic's on each drum and put two overheads over the cymbals.  The one on the floor tom was on the left of the tom next to your right knee.  Obviously in a prime spot to get smacked on a wild fill.  So, we moved that out of the way...

The real point of this story is this:  The guitarist took long strips of duct tape and ran it across his snare and 3 toms.  ALL THE WAY ACROSS RIGHT IN THE CENTER OF THE HEAD.  To his credit the guy whose kit it was kept his cool and didn't even take it off but he was clearly shaken.  

At one point in the evening he fiddled with the tape on the snare to see if it was going to leave residue behind but so far it hadn't.  

I'm going to pick up some moongel to bring to him so he can try to get rid of the tape.  BUT I'M ALSO GOING TO KEEP A BUNCH OF MOONGEL AND RINGS HANDY FOR WHEN I FILL IN FOR THE MAIN DRUMMER AND USE MY OWN KIT!  

Question:  Would you go berzerk if your friend duct taped your kit?  I'd go crazy.  

The key is to be better informed than the other person, and to offer better ways to muffle and mic the kit. Duct tape directly across the playing area of a head is stupid. But you need to offer a better way to muffle the head. If you don't know that way, learn it, then show the guy. Skip the going berzerk part - it accomplishes nothing. Combat stupidity by being better informed.

The guy keeps his kit in the guitarist's garage and we showed up with that already done.   I didn't say anything since it wasn't my kit (and I'm still kind of new to the dynamic of the group.)  

Mr. A suggests offering alternatives and that's why I'm coming with moongels etc next rehearsal.  Not only to help out the main drummer, but to have an alternative available for when I use my kit.  

If the guy's only solution was duct tape he probably doesn't get a good sound anyway.

As my old hero Bugs Bunny would say, "What a maroon!"

I'm not too keen on people messing with the sound of my kit without me around.  I have found people who just kill the drums as a means to control the sound are lacking in the imagination department.

I recently did a recording for a rock group.  I arrived at the studio with my Ayotte kit ready to go.  Set it up and did my thing.  The engineer kept complaining the drums were to live sounding and asked me to tape them down.  It became a bit of a hassle, and in the end, I ended up using the studio's 12 year old Tama Stagestar!!  He had some old Studio X heads on it, and the kit sounded literally like boxes.  The best part was, a few days later the guitar player who hired me played a rough mix. The drums sounded all Creedish, new rock reverbed out, cannon type sound.  The engineer told him it was easier to just get dead drum sounds and "juice them up in the mix" with post processing.  Whatever, I got paid.

Just like you said Drum4JC, I always keep rings in my cases just for situations like this.  

If the guy did it while the drummer wasn't there, that's not cool at all.  I usually will head someone off at the pass when they try to use duct tape on my kit, so I don't have to go berzerk.  But if it has been done while I was away, we'd have words.

Incidentally, that's one of the reasons I won't leave my kit in someone else's rehearsal space.