If you watched the Spider-Man: Homecoming trailer and thought the electronic gauntlet wielded by Bokeem Woodbine's Shocker looked familiar, your theories have been confirmed. The bit of tech has already appeared in the MCU, according to Homecoming producer Eric Carroll.
It was previously seen wielded by Crossbones in the opening battle sequence of Captain America: Civil War, suggesting that Tony Stark's Damage Control is particularly bad at doing its actual job of cleaning up and containing technology "spills". But then, maybe you could say this wasn't on his watch and the government are to blame...
Anyway, Carroll confirmed the cross-over:
“That gauntlet, you’ll recognize from the beginning of Civil War, it’s what Crossbones is using to kick the sh*t of Cap in that prologue. They scavenged it from the battle in Lagos and made a couple of upgrades, so that it’s not a pneumatic punch machine, it also delivers a pretty hefty jolt when it connects as well.”
Presumably the upgrades came courtesy of The Tinkerer on the insistence of Michael Keaton's Vulture.
Carroll also confirmed to set visit journalists that the technology Toomes and his crew of terrorists have scavenged came from the Lagos battle in Civil War, the Battle Of New York, the Sokovia Incident in Age Of Ultron and the invasion of London in Thor: The Dark World by Malekith's forces. So we can expect to see Tony Stark's tech turned against him (and the return of Vibranium, presumably) and probably Chitauri and Dark Elf weaponry (though not the black hole grenades, surely?).
Unfortunately, this causes yet another rift between the MCU and the Marvel TV shows, because the Battle Of London was shown being cleaned up by Agents Of SHIELD in the first season. Sure, it was then revealed that HYDRA had infiltrated SHIELD subsequently, but the idea of either of those institutions leaving valuable tech laying around for scavengers is ludicrous. Maybe don't pick at that too much.