This has happened to Me and my Friends a lot lately, People can do /shop, but TnT, blow their glass up, can't break blocks, but can blow other bases up with Tnt!
[quote="ImTopmass, post: 499663, member: 6154"]Doesn't TNT have to be lit with flint and steel?[/quote] No, in /shop there is also a TnT launcher, You right click the launcher in the glass and lets You survive and still be able to blow up others, like You cant ender pearl or anything, but You can leave the other players with just like 3 blocks on their island.