I am part of the group that got the SMP1, 2, 3, and 4 (another team got one from SMP4 too though) Dragon Eggs. When we first got the SMP1 egg, we had it in a 2 thick glass case. Noobs quickly broke through and tried to steal the eggs by hitting them and making them teleport. Gamekrib jeremy was there to stop them and he made it 3 thick but the noobs still broke in.When we built a museum about the adventures involved in getting a dragon egg, we built a more secure display case. Our arrangement was successful in protecting all 4 eggs. We had 4 wide glass to show all the eggs. the glass was 1 tall but 5 thick. That glass was surrounded by obsidian. The chamber itself that held the eggs is also made completely of obsidian. This arrangement takes long enough to breach that noobs can't break in. We had 8 iron and wooden doors set up as a service entrance as well.