GTA Online had a rocky start, but after all of the bugs and server issues were ironed out, it has been clean sailing for a lot of player since then. However, that all changed over the Christmas period when a huge surge of exploits, hacks, cheats and glitches came in that completely ruined the economy and made getting a shiny new Adder as easy as buying your first new pair of pants.
The newest title update for Grand Theft Auto V, update 1.09, has been release to try and combat all of the recent going-ons and happenings, and with no real content released in the latest update, it's clear that these problems have slowed down content production just a little bit.
The biggest change for any wannabe cheater is that Rockstar have now improved and bolstered up their anti-cheat system. It's so far unknown how effective it will be, but hopefully it will be able to do a good job at catching the culprits, and won't bring up any false negatives.
A lot of the glitches and exploits that have involved GTA$ and RP have also been fixed, but it wouldn't surprise me if a new one is found eventually. It's always an ongoing game of cat and mouse with cheaters and hackers, but this new patch should certainly trap a large amount of them.
If you've been gifted a large sum of money, or collected a double-quadrillion bounty from your next door neighbor, chances are this has now been removed from your account, but you won't face any penalty or bans against your name.