RS accounts can be hacked, the meaning of the word is correct on the subject, as there are forums and other sites, that users register, enter username, password and email address, when a hacker sees a vulnerability in these sites, he gets the database, now some sites store passwords in plain text, others use basic MD5 hash which can be brute forced or searching from online crackers, like
www.md5decrypter.co.uk (It has quite a big database).
After this, usually the hacker tries the same password or variations on the email address that was used to register, 75% of the time the password is the same, now that they have access to the email, they can pretty much steal ("hack") any account that is registered to that email, including: steam, runescape, forums, sites, paypal, etc.
There is not much you can do about this, just make sure you never use the same password on the accounts/sites you value.
Protection against website vulnerabilities is important, keeping your forum software up-to-date and looking for possible exploits from time to time to your forum software, and if found, just disable the forum for that time (Or the vulnerable file).
Most hackers use proxies, so theres no point in getting the IP, but yeah, some skiddies don't know shit about anonymizing themselves.
You can get everything from the database, heres an example:
user_email user_pass_convert user_passchg user_password username username_clean user_id
postmaster@choicemeds.info 0 1282368414 eba76df3******8addebd3161081d59d Ameteuncene ameteuncene 791
debovann3@aol.com 0 1282433045 a38d4b1f79459071d943e39******fd6 KillaInc. killainc. 792
havoc-disciple@hotmail.com 0 1282503881 a0a4992bae******ebfb911fe4a92c1 havoc-disciple havoc-disciple 793
mattistookool@me.com 0 1282509011 03e09363c15f9e29******28d4bc9904 deajsa deajsa 794
g.it.u.lh.ooo@gmail.com 0 1290082035 acdb0014a01******941e3179d335911 ridener??m ridenerm 1080
ms130@live.com 0 1288649225 dcfee42fa1811ab22be9******51dd4a mac_attach mac_attach 1050
stunna_superman@yahoo.com 0 1282275217 516b******6654e478a2584516e1d0b4 young-star young-star 789
mesisca89@yahoo.com 0 1282271513 4a998132e095611f6******185fe38da Mesisca89 mesisca89 788
shannunnery@ymail.com 0 1282041050 33ecb762027025b******706163025f1 Miltown_414-Goo miltown_414-goo 781
kevinhadzic@yahoo.com 0 1282160904 7000a6920e7ff9c0******d5bd1ffce1 shooter-027 shooter-027 783
bookworm3655@yahoo.com 0 1282173597 b23088b566431a******23a360a212f1 canusurviveme canusurviveme 785
mesisca89@yahoo.com 0 1282271513 4a998132e******f6e2b6e4185fe38da Mesisca89 mesisca89 788
stunna_superman@yahoo.com 0 1282275217 516bc9f884******78a2584516e1d0b4 young-star young-star 789
mdvann2@aol.com 0 1282354410 e4f831c7dd5eb92950******abb2191f deathbringer27 deathbringer27 790
underarmor79@yahoo.com 0 1282514085 1616b4035******954ea98b880ae27ff A7X_Soldiers a7x_soldiers 798
allyg@gmail.com 0 1282517907 a854bfb3fb4e7c621f******56dec101 Al_sharpton al_sharpton 799
Those were achieved by a blind SQL injection.
Basic vulnerabilities are SQL/Blind SQL injections and RFI/LFI (Remote File Inclusion/Local File Inclusion).
Links for information:
Blind SQL injectionSQL injectionRFILFI