Due to the large number of malicious registrations received by the blog recently:

In addition, I have been attacked by bored people every now and then recently (although it has no impact, it is still very annoying):

I decided to temporarily close the user registration function of the blog and clean up maliciously registered accounts (to prevent bored people from using the links of registered users to attack). As for when to open registration again, I will decide when the need arises. Anyway, there are no functions that require registered accounts to use (some articles previously required VIP access, but now except for some sensitive content, I have allowed all others).