Here is a list of the known data leeches and hogs suggested by the users of this forum:
Definitions for the purposes of this list:
leech: Something that you may not even be aware of, but is using a lot of data.
hog: An activity that uses a lot of data.
Iphone, leech: Can use gigs of data in a short time. I was told by an experienced Iphone user that this is because by default all installed apps are reloaded periodically, and that this can be controlled or turned off completely at the Iphone. I haven't verified the latter.
Video streaming, hog: The lower the resolution the better. Can be affected by use of the sometimes bashful and elusive Video Data Saver.
Chromecast, hog: Unless the default settings are changed and is not powered on except when being used.
Satellite TV receivers, leech: Satellite television seems particularly a problem, because remote DVR setting tends to prioritize On-Demand instead of live programming and you can mistakenly record a 5GB movie. There are other services such as software updates will prioritize internet over the one-way satellite feeds. This will also include on-screen guides and apps that use a tremendous amount of data, and are perfectly happy using it without you knowing about it.
Gaming consoles. leech: See kids.
Security cameras, leech, You have to send the video somewhere, then receive it somewhere else. If you're using it to watch what's going on and they're both using the same modem, it's a double-whammy.
Cloud connections, hog: Any kind of real-time cloud work - for reasons similar to streaming, things like Google Docs are especially notorious for eating data.
Social media apps, hog: Particularly Facebook and Instagram because there's no way to hide people's images and videos. Media, especially hi-res media, are a massive data sink depending upon what resolution they are converted to.
kids, hog/leech: One of the biggest, with any device connected to the Internet. Sorry parents but just a fact. Ah kids! Got to love them though!
Windows 10, leech: "Delivery Optimization", formerly known as "Updates from more than one place". It should be set to "PCs on my local network" or turned off altogether. If it's set to "PCs on my local network, and PCs on the internet" you can be sharing your Windows updates with others on the internet, meaning a LOT of data being used via upload.
Rogue web sites, hog: I've experienced one web site that suddenly went roque and started using 200 meg just to load its home page, but then in a few days it went back to normal. Constant vigilance!
The following have to do with Web pages, and can sometimes be helped by installing some sort of add-on: Pop up blocker, Ad blocker, Java script blocker, etc. One or more of these of these can make the page not work properly though:
Web page ads, hog: I use an ad blocker add-on for Firefox. Love to see those big empty spots in web pages where the ads were supposed to be. Some sites will detect it and whine. or even refuse to load. If the latter, that may be the last time I ever visit that site. I'll put up with a little whining though.
Web page videos, hog: A Java script blocker will get most of these. May have to be turned off for a site if you actually want to watch a video.
Pop up windows, hog: I use a pop up blocker add-on for Firefox.
Another data leech, at least with Windows 10, is "Delivery Optimization", formerly known as "Updates from more than one place". It should be set to "PCs on my local network" or turned Off altogether. If it's set to "PCs on my local network, and PCs on the internet" you can be sharing your Windows updates with others on the internet, meaning a LOT of data being used via upload.
Another data leech, at least with Windows 10,.....
Thanks for the info.
"WINDOWS n. The world largest and most malicious computer virus."
The New Devils Dictionary ( With apologies to Ambrose Bierce )