SCP Foundation

Firstly, your formatting is off. There is no need to press "enter" between "Special Containment Procedures:" and the text after it — these can go on the same line.

given it's entirely

Should be "its" if it's possessive. "Its" means "belonging to it" while "it's" means "it is."

At this time, there is no known method of containing or preventing instances of SCP-XXXX, […] placed agents in positions at major social media platforms that would enable the Foundation to remove and censor instances of SCP-XXXX once they are detected.

The first part (bolded) is unnecessary — having agents monitoring social media and censoring instances IS a form of containment. As such, there IS a method of containing the skip.

this is not an effective method long term, and O5 has made understanding and containing SCP-XXXX a top priority, as it's existence in the digital age is a constant threat to the exposure of the Foundation and the very things they strive to secure, contain, and protect in secret.

Lot of things wrong with this:

• The O5 generally do not get directly involved with run of the mill, euclid SCP objects. That's a Site Director at most.
• The underlined part should be deleted with extreme prejudice. Firstly, the Foundation deals with lots of online threats, and while there's a chance of these leaking out, things like amnestics exist that the Foundation uses to prevent civilian knowledge. Secondly, this comes off as an attempt to make your SCP sound artificially important and dangerous. Thirdly, and most importantly, the place for all this info is not in the Containment Procedures. The Containment Procedures are a set of instructions for personnel to follow and should not include extraneous info.

An instance of SCP-XXXX will typically be observed on social media, when people who attended the event will notice that the same entity, hereafter designated SCP-XXXX-01, was present in the background of every photo taken on the floor of such events, even if the pictures were taken at the exact same moment, but in entirely different locations at the event.

Run-on sentence which is incredibly hard to follow. Rewrite.

SCP-XXXX-01 always appears to resemble the character ████████ from ████████.

Alright, this is where I would have downvoted. I'll talk about this more in concept.

Through happenstance, Dr. ████ was browsing the website at the time and discovered the phenomenon on the front page, and quickly notified O5, who ordered the situation contained.

• The whole "Foundation employee just happens to stumble upon an anomaly" thing is overused and very, very unbelievable. You'd think this would come to their attention another way, since they literally have programs to search for anomalies.
• Like I said, no way the O5 is getting involved in this one thing. They're basically like the CEO of a big company and don't get involved in everyday matters like new anomalies.

"online trolls" being cited as the cause.

Not what trolls do.

Containment of SCP-XXXX is achieved via a two pronged approach. Primarily, the Foundation will use leveraged assets and agents placed in positions at major social media platforms, telecommunication companies, and internet service providers that would enable the Foundation to remove and censor instances of SCP-XXXX once detected.

Containment of SCP-XXXX is achieved via a two pronged approach. The Foundation will use leveraged assets and agents embedded in influential positions at major social media platforms, telecommunication companies, and internet service providers that would enable the Foundation to remove and censor instances of SCP-XXXX once detected. - ((I felt the primarily bit, implied the Foundation was mainly focusing on this approach. Which didn't seem to fit, given how much more effort and detail is put into the 'Plain Sight' approach))

However, given the size and scope of the instancing area (the internet) there is a difficulty separating an actual instance from a civilian in cosplay.

However, given the size and scope of the instancing area (the internet) there is great difficulty in separating an actual instance of SCP-XXXX from a civilian in cosplay.

All civilians that are detained for interrogation not found to be an instance of SCP-XXXX should be given class 4 amenestics and released near a local comic or game store.

This bit is confusing, you establish later that this SCP exists solely in photographic media. So why are they detaining people and amnestising them? You could put a striekthrough through this, to imply it was an earlier attempt at containment before its photographic nature was confirmed. Or cut this line entirely.

Lastly, SCP-XXXX has been shown to stop appearing as certain SCP's once they reach a certain level of popularity via Operation In Plain Sight. It is believed that this is due to SCP-XXXX wanting to help more and more SCP's gain popularity so more people will take interest in them and cosplay as them.

SCP-XXXX has stopped using the appearance of certain SCP's, once they reach a certain level of popularity via Operation In Plain Sight. It is hypothesised that SCP-XXXX has a desire to help more SCP's gain popularity, so that more people will take interest in them and cosplay as them.

SCP-XXXX will appear in pictures regardless of time and location of the picture being taken, even appearing in pictures taken at the exact same moment, but in two different locations at the event.

SCP-XXXX will appear in pictures regardless of time and location of the picture being taken, even appearing in pictures taken at the exact same moment, but in different locations at these events.

SCP-XXXX does not appear on videos either recorded or streamed, and does not appear in one on one photo ops typically offered with celebrity guests at such events.

SCP-XXXX does not appear in video footage, either recorded or streamed. And does not appear in one on one photo ops typically offered with celebrity guests at such events. - ((Little unsure about this line myself. I think maybe get someone else to give it a look over, before implementing any changes.))

The first documented occurrence of such an event took place on May 19, 20█, when a thread on popular website Reddit was besieged with photos from the San Diego Comic Con event.

The first documented occurrence of such an event took place on May 19, 20█, when a thread on the popular website Reddit was besieged with photos from the San Diego Comic Con event. - Just added 'the' to this sentence.

In this appearance, SCP-XXXX was observed appearing in photos holding several things that threatened to expose the Foundation or cause containment breaches, most notably brandishing what appeared to be SCP-3108, and an instance where SCP-XXXX was shown to be weilding SCP-3041.

In this appearance, SCP-XXXX was observed appearing in photos holding several items that threatened to expose the Foundation or cause containment breaches. One notable example was SCP-XXXX brandishing what appeared to be SCP-3108, and an instance where SCP-XXXX was shown to be wielding SCP-3041. - ((Small typo fix and slight sentence change))