After the recent spread of not one, but two new hacks in GTA Online, one of which can outright rob players of in-game cash, news of a new ban wave is welcome. Even if it isn't the great salvation that will make freeroam in public lobbies safe once more, hacker numbers might drop for a while.
That said, don't expect them to disappear entirely or for good. Past ban waves have proven that they only offer a brief respite before the bastards return and that not all of them get caught up in it. Usually, a week or so passes while the coast is clear, after which things are back to normal.
The typical indicator that a ban wave is ongoing is the sudden spike in topics and threads opened on various GTA Online community sites about being "wrongfully" banned by Rockstar. These posts almost drown out those which proclaim a period of joyous holiday in the name of the blessed ban wave.
The current ban wave is likely Rockstar's first response to the recent spread of a particularly malicious hack which effectively siphons cash away from unsuspecting victims, with session jumping being the only way to halt the process after it has begun. However, even so you could stand to lose millions due to how quickly the hack operates.

By fooling the game into thinking the victim has killed the hacker while the latter was in passive mode, the victim is forced to pay the hacker's hospital bills, which have been tweaked to cost millions of in-game cash. The hack hits the same victim on a loop until they have no money left what-so-ever.
Considering the fact that through Shark Cards, players can use real money to pay for in-game currency, this hack amounts to something pretty close to actual theft. Some jackass with a mod menu can set you back $100, or more, depending on how liberally you splurge on microtransactions.
While spawning random props and crashing lobbies is a childish way to cause a nuisance to legitimate players, this time things have elevated. The only other time hackers have managed something like this was during the whole insurance fraud hack debacle, where a similar method was used to siphon off cash from players.