I did that because i wasn't able to ask more than 5 questions a day! Why do this to me :(
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Most Helpful Guy
I can't exactly say that "how" they noticed that but basically, admins/devs can see your IP address, device and stuffs. So, they noticed that two or more accounts are being used simultaneously from the same IP and probably, the same device.
By earning 150 xper, you will reach Xper Level 2 and then you can post 5 questions and 2 takes every 24 hours. :)3