What should I use instead of downfall?

[City]

I'm trying to think of a more intelligent way to say, "bad thing" in my research paper. I cannot think of the right word though. I keep thinking of downfall, but that is not the right word.
"Companies are sometimes in the trending topics for not so ideal reasons, since they cannot control what is being said about them on the Internet. This is a "_______" of Twitter; companies may be blamed and lose customers for something that may have not even happened. However, the perks of Twitter do outweigh these "_____.""

I'm not sure what word I should use in the blanks. Can someone help?
Thank you! Sometimes it's the simplest things that give us the most trouble.

[Cassie]

Negative aspect (:

[kwingary]

shortcoming
negatives

[Summersjoy]

Decline; downhill