People should be aware

[OgNasty]

Forum administrators read the messages you send to other users.

I sent a private message to another user about deleted posts and minutes later several dozen of my posts were deleted by the 'administrator'.

Be careful with any private messages you send on this forum.

If you think the forum administrators are bad, wait until you learn about the NSA… Never think anything you do online is private or secret. It’s not. Government just doesn’t have the time or manpower yet to punish everyone for their activity. I suspect AI will change this in the future, but for now enjoy the freedom that strength in numbers provides and stop whining about the obvious.

[lovesmayfamilis]

It is possible that:

a) the user you sent the PM to reported all those posts and got them deleted, or
b) coincidentally, some random user you were arguing with earlier on a thread somewhere reported all those posts.

What you stated is actually what happened. Especially the number 2.
Some users are so obsessed that they will always be right in any argument, especially some high ranking members.
If you do not agree with their opinion, they will have to report the post to make sure they are deleted. Once the report is coming from a regular reporter who is reputable, the moderator will not give it a second thought.
I think @Lovesmayfamilis did it to me yesterday, and about 4 of my posts were deleted, as if it was not enough he went further to tag me.
If I could be tagged for nothing, that means if my account commits semi-plagerism, I will not last more than 2sesc in the forum.
God please save your people o...

Again, you think a lot about your importance to me. I warned you, you did not hear. But note that my messages were also deleted, as I was forced to explain to you twice that you were wrong. But you still don't get it. The moderators themselves made the right conclusions by removing all unnecessary messages from the topic two years ago.
I did not report your posts, so do not make yourself a victim, for which someone is constantly hunting. 

[LoyceV]

Some users are so obsessed that they will always be right in any argument, especially some high ranking members.
If you do not agree with their opinion, they will have to report the post to make sure they are deleted.

That's not how reporting works: posts aren't deleted if don't break the forum rules. If you already know for instance that your argument is off-topic, you could have created a new topic for it.

Once the report is coming from a regular reporter who is reputable, the moderator will not give it a second thought.

Then why do I have 92 bad and 294 unhandled reports? Let me answer that: Mods follow their own judgement.

I think @Lovesmayfamilis did it to me yesterday, and about 4 of my posts were deleted

If you believe those posts shouldn't have been deleted, you should present your case in a new topic in Meta.

[KingsDen]

Again, you think a lot about your importance to me. I warned you, you did not hear. But note that my messages were also deleted, as I was forced to explain to you twice that you were wrong. But you still don't get it. The moderators themselves made the right conclusions by removing all unnecessary messages from the topic two years ago.
I did not report your posts, so do not make yourself a victim, for which someone is constantly hunting. 

Sometimes, it's good to speak out than harbour. Within me I was 100% convinced that you reported my posts. I'm very sorry for the wrong accusation.
Now, that the subject matter (Res) is deleted, can you please remove the tag on my profile. Thanks in anticipation.

I think @Lovesmayfamilis did it to me yesterday, and about 4 of my posts were deleted

If you believe those posts shouldn't have been deleted, you should present your case in a new topic in Meta.

I am not that much concerned when my posts are deleted. Though I saw that last during my newbie days, except this recent one.
What I tried doing those days was to try reply the private message to let the sender tell me the kind of messages that goes against the forum standard 
Personlly, I don't think deleted posts worth creating a new topic.