Leave it to hackers to make something bothersome out of something good. This week, anyone can grab Grand Theft Auto 5 for free from the Epic Games Store, which proved to be such a popular offer that the influx of users crashed the service on the first day. Since then, the massive influx of players turned out to include a large throng of hackers, too.
GTA Online is no stranger to hackers. For years, the PC, Xbox 360 and PlayStation 3 versions of the game suffered from the constant presence of cheaters. Rockstar fought an uphill battle to mitigate the situation with increasingly severe punishments and an ever-evolving anti-cheat system, but the cheaters were seemingly always a step ahead.

During some of the worst periods, hackers would siphon millions of GTA$ from players with an insurance dupe, drop cash on characters which would identify the victim as the hacker and boot them into a bad sport lobby, or routinely crash lobbies by spawning infinite props.
With varying degrees of desperation, the in-game anti-cheat was continually updated by Rockstar, and at one point the system got so trigger happy that it disabled single-player mods outright — but cheaters still got past.
In recent years, thankfully the problem subsided on PC, and the permanent closure of character transfers eliminated it on Xbox One and PlayStation 4 entirely.
However, ever since GTA 5 went free on EGS, reports have been pouring in of multiple cheaters being present in pretty much every public lobby, making GTA Online once again borderline unplayable on PC unless you stick to private instances. These, however, disable certain activities.
Rockstar has had a lot of experience dealing with cheaters in GTA Online over the years, so this is likely due to the sudden influx of massive numbers of new players. The ability to freely create an entire new account makes the threat of a ban irrelevant.