Got owned after hacking...?

[OptiSTR]

So i started up at difficulty 7, as many said its the best difficulty to start at.
I had a 3 priority 4\3 systems next to me.
I destroyed the warp gates in 2 of them, the 4th one i wanted to invade.
In one of the lower priority systems there was a data bank, so i built 900 ships and a hacker,
and flew to the system. at first all went well, my ships held off the fire, while the hacker did its job.
After he was done, i had like 300 ships left, so i retreated.
back in my system, i placed all my ships on the wormhole to defend, but the AI followed me.
And not only that, but he followed me with very powerful cruisers (one of them was tractor beam cruiser).
He cut through my defenses like there were not there, and i barely scratched him...
basically i was not an invasion fleet, but a built up fleet + reinforcements.
So my question is, is the only way to hack is to first capture the system?
Apparently if i stay in a system for too long, without capturing it, the AI will overwhelm me with reinforcements and local cruisers spam....

Any tips on how to hack properly?

[Rainbowsand]

First, those backups self-d if you cap the planet; second, your losses were too high. To hack at 7 difficulty you need full caps of everything plus a lot of mercenaries - neinzul cruiser is a must - so you kill zombies faster than they kill you. Even then hacking is a risky proposition, consider avoiding it.

[Kahuna]

Any tips on how to hack properly?

http://www.arcengames.com/forums/index.php/topic,14774.msg163636.html#msg163636

Before you start hacking you should check your Hacking Progress Balance. If your Hacking Progress Balance goes below 0 the AI will "get crazy". In other words.. don't hack if you don't have enough HPB. HPB increases when the AI Progress increases. Of course you can hack even if HPB is below 0 but it will be much harder and you must be prepared for all kind of stuff. Not only will the AI reinforce the planet you're hacking but it will also send attacks on other planets. Like a fleet of Raid Starships that will attempt to destroy your Home Command Station etc.

so i built 900 ships and a hacker

You shouldn't build ships just for x purpose. You should have Space Docks on loop constantly reinforcing your fleet. When you really need your ships you wont be able to build them fast enough. (Don't build Mercenaries. They're way too expensive compared to what they do. If you have too much resources then use your fleet. Attack. Beachhead. Whatever.)

He cut through my defenses like there were not there

Check out the "3. Defense" part.
http://www.arcengames.com/forums/index.php/topic,13369.0.html

http://www.arcengames.com/forums/index.php/topic,14270.msg163060.html#msg163060

So my question is, is the only way to hack is to first capture the system?

If you capture the system you won't be able to hack it anymore. That's the point of hacking.. to get stuff without having to capture the system and thus increase AIP.

Apparently if i stay in a system for too long, without capturing it, the AI will overwhelm me with reinforcements and local cruisers spam....

Staying in an AI system just puts the system on alert which makes the AI reinforce that planet. But that's nothing crazy. The AI will just spawn a couple of ships once in a while. Though eventually (after a couple of hours) there will be hundreds of ships. It was probably the hacking that made the AI "go crazy". Also.. what do you mean by "cruiser"?

[OptiSTR]

Am ok thanks.
Now another question, do i need to build a specific hacker in the enemy system,
or can i built the hacker in my system and send it to the enemy system?
And, by cruisers i mean large battle ships (5 of them destroyed my 400 remaining ships,
came to my command ship, took down the force field in seconds...).

[Kahuna]

or can i built the hacker in my system and send it to the enemy system?

Yes if I remember correctly the Hacker isn't stationary. You can move it.

And, by cruisers i mean large battle ships (5 of them destroyed my 400 remaining ships,

I still don't know what you mean by "large battle ship". You can see the ship's name in it's tool tip/description.
Anyway.. it sounds like your ships are being countered by the AI ships. You need to pay attention to the Hull types and Damage Multipliers.