To all the infantry sitting back and saying tanks are OP:

There are several ways to kill a good tank, some are easier than others but I will mention a few of them.

Get a cheap rail tank.

Required Skills: None
An easy way to take out the very best of tanks is get a militia tank, put a large militia rail gun on a Sica or a Soma and just sit in an elevated position and wait for said tank to come.

-Sica:
High:
2 Militia Railgun Damage Mods
1 Heavy Milita Shield Extender
Low:
2 Militia Railgun Ammo Mods

-Soma:
High:
2 Militia Railgun Damage Mods
Low:
Milita Heavy Armor Repairer

Just activate the two damage mods when you spot the tank, and blast him.

Trap the tank.

Required Skills: Demolitions level 2, some SP into swarms the higher the skill the better.
Wait until the tank gets inside the city or a closed off area, put remote explosives and proximity mines on the exit of the city and get on a somewhat elevated position, wait until you see the tank and when you do throw all the av you have at him/her, AV nades, swarms, other AV weapons. Watch the tank to see when he boosts off to escape the city. When he passes over the remotes press the button to detonate them, the proximities will automatically explode.

-It works better if you have multiple swarmers.
-If you have higher level demolitions use all the proximities and remotes you can.
-It's much more effective with a tank attacking him/her aswell.

Car bombs.

Required Skills: Demolitions level 1.
Ok, this is a fun one, take a militia LAV (or a blueprint if possible) and put as many remote explosives on to the hood of the LAV as possible. You can sit in the LAV and watch the map to find the tank. When you find it flank around the back of it and turn on the fuel injector and ram into the BACK of the tank (weakest part of the tank). Then all of a sudden... BOOOOM!... + 150 Tank Destroyed + 50 Kill.

Thanks for reading and have fun destroying tanks!