Tell that to the Hola and Honey extensions. They're known to be a botnet and for this kind of abuse for years yet you can still find them everywhere in the App/Play Store...and _so_ many tech related youtube channels keep advertising for them blindly, it's ridiculous.
I just figured Honey was kind of like spyware, collecting information about what people bought online.
If you look at the extracted codebase, it reads like a malware implant that's designed to give some blackhat traffic for their own army of clickbots.
Hola on the other hand is basically an origin obfuscator, and they route traffic through other browser extension instances.
That's how they "unlock" websites and what their proxy feature is about. Note that this is an http proxy only, and hola sniffs all local passwords and cookies, too.
So they can abuse your user account for lots of stuff without your consent, and they did that in the past, too. (A search for DDoS and hola reveals lots of incidents and news reports)