Well, most of them have full suit, so that doesn't help. We could find every gap in bedrock (are those still generated?) under our territory and build our base around drop-chutes, but other than that we need containment traps.
Are you sure that nuclear blasts are ineffective? ...well, I guess they might be effective on the power generators that the raiders use...
Newsflash: One shot with a cannon is apparently above reproach as a rule of thumb.
I propose finding where the Q-suited thugs live and fighting a one-shot war with them...
MAD doesn't work when most people don't carry uranium around with them...
Yeah, I know that would probably be considered griefing (In our defence, "one shot" seems like a fairly open invitation, even if the actual rule is to avoid scorched-earth bombardment.) but the only weakness of Q-suit seems to be the supply chain. As long as a high-tech home base exists, they are invulnerable. The only way I can think of to attack them is through guerrilla sabotage. We aren't allowed to detpack stuff with ITNT (pity, that); nuclear warfare sounds like a good way to get banned; the only thing I can think of besides stealing fuel is vampire wires.
Style 1 involves leaving a matter generator. Admins may object, probably very expensive
Step 1: find their base.
Step 2: locate an out-of-the-way cranny with an exposed main power feed
Step 3: place matter generator
Step 4: hope they don't find it
How much energy can a scrapless Matter Generator soak up before becoming full of UU?
Style 2 involves placing blocks and leaving trail
Step 1: find their base
Step 2: locate exposed wire
Step 3: use one-way cable at our base and lay long wire to leach power. Loss is of no concern, them not having it is more important than us having it.
The audacity may earn us style points, but it probably isn't practical, involves modifying the builds of others, and invites revenge.
Style 3 has nothing in it admins can complain about and is fairly hard to trace, but is risky. We could stand to lose many E- and L- crystals.
Step 1: Load up on lapotron crystals and energy crystals.
Step 2: find their base
Step 3: drain all accessable energy reserves
Step 4: /home
Step 5: repeat occasionally
Probably the most "legit" strategy.
Alternate plan:
Assume they use nuclear power.
Fill up on lava buckets.
Find their base
(optional) Strip the place of everything stealable.
Find the reactor.
Donate all our lava buckets and /home immediately. We destroyed no blocks and used no explosives, so I would imagine that some would call it a legit raid.
Something tells me that not everyone will think so, though.
If they have an ice factory cooling system, sabotage can be made time-delayed (though more iffy) and will look more like an accident.
Tl;dr: Q-suit makes having power into having godmode. Denying power seems our only option.