Kim Dotcom, the founder of defunct Megaupload service, has finally fully launched his follow-up service with Mega — a site that offers 50GB of free cloud storage and ultrasecure ways to transmit files to friends.

Mega opened for some users on Friday, but it didn’t open for the public until Saturday. The service gives new users 50GB of storage for storing and sharing music, movies, documents, and other files. If you want even more storage, you can pay a monthly fee — 500GB of storage runs €9.99 ($13), 2TB of storage costs €19.99 ($27), and 4TB of storage runs €29.99 ($40). The service has lots of encryption, so much that Mega will not know what kind of files users are uploading.

Dotcom clearly is trying to use Mega as more powerful and secure version of Megaupload, which the U.S. government shut down in a spectacular fashion. Dotcom was charged with enabling piracy on a massive scale. Prosecutors have been trying to have Dotcom extradited to the U.S., but New Zealand’s legal system has provided him some cover so far.

“The launch of Mega is not about mocking any government or Hollywood — this is about our right to innovate and start a new business.” Dotcom said at his launch event for Mega last night. “What we are offering is a smarter, faster, and more secure way of cloud storage. And we are fully assured by our legal team that we are in compliance with the law.”

Some early users complained the site was loading and behaving slowly. Dotcom addressed that issue on Twitter, saying that demand for the service is massive and should be resolved.

“If you are currently experiencing slow access to #Mega its because of the unbelievable demand,” Dotcom said in a tweet early this morning. “We are working on more capacity.”

50GB of free cloud storage is an immensely nice offer, one that trumps what Dropbox, Google Drive, SugarSync, Microsoft SkyDrive, and other storage players offer for free. Will you use Mega’s service?

Check out some of the offbeat launch event of Mega in the video below: