Today I noticed that Facebook shows my device when I'm online (mobile or web). This is against the privacy that I want. I don't want anybody know that whether I'm using mobile or web. I saw this report, which says there is no way to hide this (up to the time of writing this question), is there any possible way to prevent showing mobile or web in Facebook chat? Or we should communicate with Facebook team?
By uninstalling Facebook app or Facebook Messenger from your phone you can prevent this. There is no other way to hide this.
This is new design of Facebook and if you have installed Facebook apps (ex: Facebook for iPhone and Android), it will show phone icon next to your name.
If you have problem with this, you are free to report about this to Facebook.