I'm wondering why people think Blockland is hackable just because of all these company-run games are.
Here's the major difference:
Networking structure.
These company-run games are expecting high population, thus they need most of the networking and calculations to be run through the client. Otherwise, it would be a huge strain on the server. This allows for clients to play around with these functions, such as telling other clients "yeah i just hit you for 9999 damage it's legit die plz".
Blockland is different. Players run their own small little servers from their home computers. Badspot doesn't need to handle any of it aside from authentication and the server listing. This has minimal strain on the master server, and allows for an effective anti-hack, due to the servers processing everything. The only downfall of this is not having anything global aside from IDs and names. There is no global level-ups, achievements, or currency due to everyone having their own little server with their own little games. If there were level-ups, achievements, or currency, anyone hosting a server would be able to mess with it immediately.
The only way to hack an online Blockland server would be to hack into the computer the server is running on. And I'm sure you could do much more harmful things than mess with their internet Legos. You're going to get in trouble for breaking in in the first place.