When the merit system was first implemented, demerited of one's merit could be done by other users because it was a bug they had not fixed. But after theymos have fixed it since then, it will no longer be possible to demerited it, except in case of merit abuse such as merit trading, incorrectly entering the amount when sending and so on. Thyemos may still be able to do so if the sender asks it to cancel the transaction for obvious reason.

Quote from: bill gator on January 24, 2018, 11:30:45 PM

Theymos, bug : Sending negative merit increases your spendable merit, please advise and fix.

I tested it on another user, gave them negative my total spendable increased. I gave them back their merit and now my contribution is +0 merit to their post, which is funny at best, but definitely something I'm sure you're already looking into.

Quote from: Lauda on January 24, 2018, 11:31:27 PM

Quote from: Lutpin on January 24, 2018, 11:29:19 PM

Quote from: entr on January 24, 2018, 11:27:58 PM

If there is no demeriting right now. How does this guy at the topic -link below- demerited by the same guy?

Quote

Merited by crairezx20 (-10), crairezx20 (-10), crairezx20 (-10)

https://bitcointalk.org/index.php?topic=2605767.140

Did you forget to limit the merit you can send to positive numbers?

Tested on Lutpin:
Entered -10.
His points dropped by -10.
My sMerit went up by 10.

I assume, the 50 limit doesn't apply here and I could neg. you by a few thousands.
Update: Tested. There is no limit on the negative numbers. Sorry Luptin. Cheesy