Love them or hate them, loot boxes are a contentious issue in the videogame industry. Many notable critics, including Jim Sterling, AngryJoe, and TotalBiscuit have been highly critical of the system, spurred on by recent revelations that titles such as Star Wars Battlefront II and Middle-earth: Shadow of War will be following in the footsteps of Overwatch and including micro-transactions and loot boxes.
They, along with many others critics and gamers alike, have likened loot boxes to playing slot machines in a casino, describing them as a highly addictive form of gambling. The similarities are definitely there: paying real world money to test your luck and hopefully receive some high level loot (aka "the jackpot") rather than a dirge of largely useless, filler items (aka the "small wins").
Now, a petition has been started to label loot boxes as gambling under UK law in order to reduce the negative impact they can have on gamers, in particular those who may be vulnerable to addictive behaviour. If you wish to sign the petition, you can do so here (though you must be a UK citizen).