I'll admit I use mods sometimes on 360, I don't always use my mods as I like to play proper matches aswell.
Only people I've frozen though are other troll modders. I generally hate other modders as they just ruin things and troll for no reason, I especially hate the type of modder who wants to be king of the game, what I mean by this is the type of modder on a power trip who just HAS to be the sole modder in any one server so he gets all the friend requests and messages from kids sucking up to him in the hope of getting a modded Sultan RS out of it and who wants people to try to attack him so he can troll them out of 'retaliation' in order to exert some kind of power over them, honestly, the amount of times I have entered a lobby and spawned a few cars only to have a message pop up informing me that some noob has tried to freeze me simply for being another modder. Of course I occasionally take great pleasure in trolling the odd 10 year old with constant explosions/burnings/spawnings/deletion of vehicles for noticing that I am a modder and sending me rude, impolite messages along the lines of 'Spawn me a Sultan RS, black with blue underglow now!', rude little pr*cks
The main reason I mod is to make use of the map mods and cars I can spawn for the lobby aswell as some funny vehicles, planes, hot air balloons etc.
So yeah I mod myself but I simply cannot defend what some of these modders do, ruining it for everyone for no reason, I played the game both online and off for 5 solid years before I decided to make a modded version, purely so I could try something new with the game, I still pop in my original, retail disc of IV at times as well (I only mod TBOGT)